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This review presents the advances in polymeric materials achieved by extrusion and injection molding from lignocellulosic agroindustrial biomass. Biomass, which is derived from agricultural and industrial waste, is a renewable and abundant feedstock that contains mainly cellulose, hemicellulose, and lignin. To improve the properties and functions of polymeric materials, cellulose is subjected to a variety of modifications. The most common modifications are surface modification, grafting, chemical procedures, and molecule chemical grafting. Injection molding and extrusion technologies are crucial in shaping and manufacturing polymer composites, with precise control over the process and material selection. Furthermore, injection molding involves four phases: plasticization, injection, cooling, and ejection, with a focus on energy efficiency. Fundamental aspects of an injection molding machine, such as the motor, hopper, heating units, nozzle, and clamping unit, are discussed. Extrusion technology, commonly used as a preliminary step to injection molding, presents challenges regarding fiber reinforcement and stress accumulation, while lignin-based polymeric materials are challenging due to their hydrophobicity. The diverse applications of these biodegradable materials include automotive industries, construction, food packaging, and various consumer goods. Polymeric materials are positioned to offer even bigger contributions to sustainable and eco-friendly solutions in the future, as research and development continues.
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The agricultural industries generate lignocellulosic wastes that can be modified by fungi to generate high value-added products. This work aimed to analyze the efficiency and the cost-effectiveness of the bioconversion of sugarcane and cassava bagasses using low-cost homemade enzymatic cocktails from Aspergillus niger LBM 134. Both bagasses were pretreated with a soft alkaline solution without any loss of polysaccharides. After the hydrolysis, a 28% of conversion to glucose and 42% to xylose were reached in the hydrolysis of sugarcane bagasse while an 80% of saccharification yield, in the hydrolysis of cassava bagasse using the homemade enzymes. Furthermore, a more disorganised surface and no starch granules were observed in the sugarcane and cassava bagasses, respectively. The bioethanol yield from sugarcane and casava bagasses was predicted to be 4.16 mg mL-1 and 2.57 mg mL-1, respectively. A comparison of the cost of the homemade and the commercial enzymes was carried out. Similar hydrolysis percentages were achieved employing any enzyme; however, it was 1000-2000 times less expensive using the homemade cocktails than using the commercial enzymes. Therefore, the cost of obtaining glucose from bagasses was most expensive when applying the commercial enzymes. Moreover, the hydrolysis of the cassava bagasse was most efficient with the homemade cocktails. The importance and novelty of this work lie in the similar performance and the lower cost of the homemade cocktails from the fungus A. niger LBM 134 compared with the commercial enzymes on the hydrolysis of the sugarcane and cassava bagasses.
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Manihot , Saccharum , Celulose , Glucose , Fungos , HidróliseRESUMO
RESUMO Os ácidos carboxílicos (ACs) são componentes químicos de base produzidos principalmente a partir da plataforma petroquímica. Entretanto, em razão de impactos ambientais, risco de escassez e elevados preços do petróleo, a produção biológica de AC por meio da digestão anaeróbia de recursos renováveis de baixo custo, como resíduos orgânicos das atividades agroindustriais, vem recebendo atenção crescente. Nesse contexto, o presente artigo objetiva discutir o processo de digestão anaeróbia aliada ao alongamento de cadeia carboxílica, a fim de orientar tomadas de decisão, como, por exemplo, escolha do substrato e definição das condições ambientais e dos parâmetros operacionais. Em geral, as condições que apresentam melhor viabilidade para produção de ácidos carboxílicos de cadeia média (ACCM) são: pH próximo a 6,0; temperatura mesofílica, já que oferece maior estabilidade operacional e os rendimentos obtidos em condições termofílicas não se mostram muito superiores; pressão parcial de hidrogênio (PPH) próxima a 10-5 aliada à limitação de CO2; tempo de residência celular (θc) inferior a 5 dias; e tempo de detenção hidráulica (TDH) baixo para sistemas contínuos. Uma das configurações mais promissoras é o uso de sistemas de dois estágios utilizando baixo pH como inibidor da metanogênese e extração de ACs em linha, para evitar a inibição devido à toxicidade dos produtos.
ABSTRACT Carboxylic acids (CA) are basic chemical components produced mainly through the petrochemical platform. However, due to environmental impacts, risk of scarcity and high petroleum prices, organic production of CA from the anaerobic digestion of low-cost renewable resources, such as organic wastes from agro-industrial activities, has been receiving increasing attention. In this context, the present paper aims to discuss the process of anaerobic digestion allied to the carboxylic chain elongation process, in order to guide decision making such as substrate choice, definition of environmental conditions, and operational parameters. In general, the conditions that present the best viability for MCCA production are: pH close to 6.0; mesophilic temperature since it offers greater operational stability and the yields obtained under thermophilic conditions are not much higher; hydrogen partial pressure (HPP) close to 10-5 combined with CO2 limitation; solids retention time (θc) < 5 days and low hydraulic retention time (HRT) for continuous systems. One of the most promising configurations is the use of two-stage systems using low pH as a methanogenesis inhibitor and inline CA extraction to avoid inhibition due to product toxicity.
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Bioactive peptides can provide health benefits due to different mechanisms. The aims of the present study are to produce bioactive peptides from bovine and goat milk subjected to the proteolytic activity of Aspergillus oryzae and Aspergillus flavipes enzymes, as well as to assess their putative antimicrobial and antioxidant activity. Bioactive peptides were successfully generated from proteases of fungi cultivated in solid-state fermentation. The generated peptides were effective against all tested bacteria and fungi. There was antioxidant activity, up to 92.5% DPPH reduction and ORAC stabilization at 52.5⯵mol⯵L-1 of Trolox Equivalent. The generation of milk-specific sequences peptides in the samples was obtained through 2D-PAGE fractioning followed by mass spectrometry (ESI-MS/MS). Based on results in the present study, milk bioactive peptides presenting broad antimicrobial action and antioxidant activity spectra can be cost-effectively produced through solid-state fermentation. The herein addressed approach can be valuable for the pharmaceutical and food industries.
Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Leite/metabolismo , Peptídeo Hidrolases/metabolismo , Peptídeos/farmacologia , Animais , Anti-Infecciosos/metabolismo , Antioxidantes/análise , Antioxidantes/metabolismo , Aspergillus/citologia , Aspergillus/enzimologia , Aspergillus oryzae/citologia , Aspergillus oryzae/enzimologia , Bovinos , Eletroforese em Gel Bidimensional , Fermentação , Proteínas Fúngicas/metabolismo , Cabras , Resíduos Industriais , Leite/microbiologia , Peptídeos/química , Peptídeos/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
Abstract Objective. To evaluate the impact of two microbial additives on the productive behavior, zoometric, incidence of diarrhea and mortality of post-weaning piglets. Materials and methods. A total of 120 piglets (Duroc / Yorkshire / Landrace) were used, divided into three groups of 40 animals each, control (T1); microbial preparation A (T2) and microbial preparation B (T3). The T2 contained Lactobacillus acidophilus, Lactobacillus bulgariccus y Streptoccus thermophilus. The T3 was composed of microorganisms of T2 plus Saccharomyces cerevisiae and Kluyveromyces fragilis (L-4 UCLV). We used a completely randomized design where we evaluated, live weight, daily mean gain, height: raised at the cross, raised to the rump, body length, for both sexes and diarrheal incidence and mortality. Results. Live weight in the offspring (males and females) consuming microbial additives were higher and of these were higher in T3. Regarding the average daily gain, the largest increases were found in T3 group. Elevated to the cross, raised to the rump and length of body was greater (p<0.05) in T2 and T3 at birth; while at the end of the study in T3 it was superior. The incidence of diarrhea was higher (p<0.05) in the control group. The animals of the groups that consumed microbial preparation had no deaths during the study. Conclusions. The use of the microbial additives evaluated had a positive effect on the productive and zoometric behavior of the piglets. In addition, the reduction of the incidence of diarrhea and mortality of the animals was achieved.
Resumen Objetivo. Evaluar la repercusión de dos aditivos microbianos en el comportamiento productivo, zoométricos, incidencia de diarreas y mortalidad de lechones post-destete. Materiales y métodos. Se emplearon 120 lechones (Duroc/Yorkshire/Landrace), distribuidos en tres grupos de 40 animales cada uno, control (T1); preparado microbiano A (T2) y preparado microbiano B (T3). El T2 contenía Lactobacillus acidophilus, Lactobacillus bulgariccus y Streptoccus thermophilus. El T3 estuvo compuesto por microorganismos del T2 más Saccharomyces cerevisiae y Kluyveromyces fragilis (L-4 UCLV). Se utilizó un diseño completamente aleatorizado donde se evaluó, peso vivo, ganancia media diaria, talla: alzada a la cruz, alzada a la grupa, largo de cuerpo, para ambos sexos e incidencia diarreica y mortalidad. Resultados. Peso vivo en las crías (machos y hembras) que consumieron aditivos microbianos fueron superiores y de estos fueron mayores en el T3. En cuanto a la ganancia media diaria, los mayores incrementos se encontraron en el grupo T3. Alzada a la cruz, alzada a la grupa y largo de cuerpo fue mayor (p<0.05) en el T2 y T3 en el nacimiento; mientras que al final del estudio en el T3 fue superior. La incidencia de diarrea fue mayor (p<0.05) en el grupo control. Los animales de los grupos que consumieron preparado microbiano no presentaron muertes durante el estudio. Conclusiones. El uso de los aditivos microbianos evaluados produjo un efecto positivo en el comportamiento productivo y zoométrico de los lechones. Así mismo, se logró la reducción de la incidencia de diarreas y mortalidad de los animales.
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This study aimed to evaluate the properties of xanthan gum produced by Xanthomonas campestris pv. campestris 1866 and 1867 from lignocellulosic agroindustrial wastes. XG was produced using an orbital shaker in a culture medium containing coconut shell (CS), cocoa husks (CH), or sucrose (S) minimally supplemented with urea and potassium. The XG production results varied between the CS, CH, and S means, and it was higher with the CH in strains 1866 (4.48 g L-1) and 1867 (3.89 g L-1). However, there was more apparent viscosity in the S gum (181.88 mPas) and the CS gum (112.06 mPas) for both 1866 and 1867, respectively. The ability of XGCS and XGCH to emulsify different vegetable oils was similar to the ability of XGS. All gums exhibited good thermal stability and marked groups in the elucidation of compounds and particles with rough surfaces.
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Agricultura , Resíduos Industriais , Lignina/metabolismo , Polissacarídeos Bacterianos/biossíntese , Xanthomonas campestris/metabolismo , Varredura Diferencial de Calorimetria , Cocos/metabolismo , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , ViscosidadeRESUMO
The current study has assessed whether the oral and/or dermal exposure of C57Bl/6 J mice to tannery effluent (a complex pollutant consisting of xenobiotic mixtures) could damage their olfactory functions, as well as whether it changes their aversive behavior in the inhibitory avoidance test. Accordingly, the animals were distributed in groups which were exposed or not to this xenobiotic through two different routes (oral and dermal), for 15 days. The effluent group subjected to oral exposure received drinking water containing 5% tannery effluent, whereas the animals in the dermal group were exposed to raw tannery effluent for 1 h/day. The animals dermally exposed to the tannery effluent (males and females) have shown the highest latency to find palatable food in the buried food test. The shortest time spent by the animals (orally or dermally) exposed to tannery effluent in the safety zone of the apparatus used in the predator exposure test, as well as the longest time spent by them in the aversive zone, have shown failures in their perception to the risk represented by the presence of the predator (cat). The passive avoidance test results have shown that the dermal exposure to tannery effluent led to partial memory deficit in male and female mice; therefore, the present study has confirmed the tannery effluent toxicity to mammals. Moreover, the present study was pioneer in demonstrating that the dermal exposure to this xenobiotic, even for a short period-of-time, can change the olfactory and cognitive functions of animals, as well as lead to harmful consequences to their health.
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Aprendizagem da Esquiva/efeitos dos fármacos , Resíduos Industriais/efeitos adversos , Transtornos da Memória/induzido quimicamente , Percepção Olfatória/efeitos dos fármacos , Curtume , Poluentes Químicos da Água/toxicidade , Administração Cutânea , Administração Oral , Animais , Feminino , Resíduos Industriais/análise , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Filamentous fungi are microorganisms widely known for their diverse biochemical features. Fungi can efficiently invade a wide variety of substrates under operational conditions producing numerous bioproducts of interest, such as enzymes, organic acids, aromatic compounds and colorants. An additional interesting characteristic of some fungi is their safety classification for different uses, which guarantees that the bioproducts obtained from them do not contain any toxic component deleterious to humans. Rhizopus oryzae is among this group of fungi and is classified as a GRAS filamentous fungus, commonly used for production of some oriental traditional foods. It is mainly recognized as a good producer of lactic acid; however, its potential for other biotechnological processes is under study. This review analyzes and discusses the current scientific and technical contributions which may maximize the potential of R. oryzae as a producer of different compounds of industrial interest.
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Fermentação , Microbiologia de Alimentos/métodos , Rhizopus/metabolismo , Biocombustíveis , Biotecnologia , Indústria Alimentícia , Humanos , Ácido Láctico/biossínteseRESUMO
Waste effluent from the tannery industry is a major source of environmental pollution. Considering that the bird intake of water contaminated with tannery effluent constitutes a potential genotoxic source, especially for birds inhabiting areas closest to tanning industries, the aim of this study is to assess the possible mutagenic effects that the intake may have on Melopsittacus undulatus (Australian parakeet). In order to do so, adult male and female M. undulatus were distributed in two experimental groups: control (drinking water) and TE (5%). After 60 days of exposure, the micronucleus test, as well as tests looking for other nuclear abnormalities in the peripheral blood of the birds were performed. The male and female birds exposed to the pollutant have presented the highest total number of nuclear abnormalities, as well as increased individual abnormalities such as nuclei with symmetrical constricted bi-lobed/bi-nucleated erythrocytes, indented nuclei and micro-lobed nuclei (top)/micro-nuclei (bottom). In addition, the exposure to TE has caused a nuclear variant increase rarely reported in the literature concerning poultry erythrocyte nuclei. The birds exposed to the pollutant have presented the highest frequency of displaced nuclei forming different rotation/displacement angles within the cells. Therefore, the current study confirmed the toxicological potential of TE and was pioneer in showing that male and female M. undulatus exposed to pollutant present the highest frequency of erythrocyte nuclear abnormalities, thus corroborating the initial hypothesis herein presented.
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Resíduos Industriais/análise , Melopsittacus/genética , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Mutagênicos/toxicidade , Curtume , Poluentes Químicos da Água/toxicidade , Animais , Austrália , Dano ao DNA , Monitoramento Ambiental/métodos , Eritrócitos/efeitos dos fármacos , Eritrócitos/patologia , Feminino , Masculino , Melopsittacus/sangue , Testes para Micronúcleos , Estrutura Molecular , Mutagênicos/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/químicaRESUMO
The tons of organic waste that are annually generated by agro-industry, can be used as raw material for methane production. For this reason, it is important to previously perform biodegradability tests to organic wastes for their full scale methanization. This paper addresses biodegradability, methane production and the behavior of populations of eubacteria and archaeabacteria during anaerobic digestion of banana, mango and papaya agroindustrial wastes. Mango and banana wastes had higher organic matter content than papaya in terms of their volatile solids and total solid rate (94 and 75% respectively). After 63 days of treatment, the highest methane production was observed in banana waste anaerobic digestion: 63.89ml CH4/per gram of chemical oxygen demand of the waste. In the PCR-DGGE molecular analysis, different genomic footprints with oligonucleotides for eubacteria and archeobacteria were found. Biochemical methane potential results proved that banana wastes have the best potential to be used as raw material for methane production. The result of a PCR- DGGE analysis using specific oligonucleotides enabled to identify the behavior of populations of eubacteria and archaeabacteria present during the anaerobic digestion of agroindustrial wastes throughout the process.
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Agricultura , Anaerobiose , Archaea/isolamento & purificação , Bactérias/isolamento & purificação , Biocombustíveis , Reatores Biológicos , Resíduos Industriais , Metano/biossíntese , Resíduos Sólidos , Archaea/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Carica , DNA Bacteriano/análise , Mangifera , Metano/isolamento & purificação , Plantago , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Eliminação de Resíduos , RibotipagemRESUMO
Las toneladas de residuos orgánicos que se generan anualmente en la agroindustria pueden aprovecharse como materia prima para la producción de metano. Para que los residuos orgánicos se puedan convertir a metano a gran escala, es importante que previamente se realicen sobre ellos pruebas de biodegradabilidad; un parámetro importante que conviene establecer es su potencial bioquímico de metano. En el presente trabajo se estudió la biodegradabilidad, la producción de metano y el comportamiento de poblaciones de eubacterias y arqueobacterias durante la digestión anaerobia de residuos de plátano, mango y papaya provenientes de la agroindustria, adicionando un inóculo microbiano. Los residuos de mango y plátano tenían mayor contenido de materia orgánica (94 y 75 %, respectivamente) que el residuo de papaya con base en su relación sólidos volátiles/sólidos totales. Después de 63 días de tratamiento, la mayor producción de metano se observó en la digestión anaerobia del residuo de plátano: 63,89 ml de metano por g de demanda química de oxígeno del residuo. Los resultados del potencial bioquímico de metano demostraron que el residuo de plátano tiene el mejor potencial para ser usado como materia prima en la producción de metano. A través de un análisis por PCR-DGGE con oligonucleótidos específicos se logró evaluar el tamaño y la composición de las poblaciones de eubacterias y arqueobacterias presentes en la digestión anaerobia de residuos agroindustriales a lo largo del proceso.
The tons of organic waste that are annually generated by agro-industry, can be used as raw material for methane production. For this reason, it is important to previously perform biodegradability tests to organic wastes for their full scale methanization. This paper addresses biodegradability, methane production and the behavior of populations of eubacteria and archaeabacteria during anaerobic digestion of banana, mango and papaya agroindustrial wastes. Mango and banana wastes had higher organic matter content than papaya in terms of their volatile solids and total solid rate (94 and 75 % respectively). After 63 days of treatment, the highest methane production was observed in banana waste anaerobic digestion: 63.89 ml CH4/per gram of chemical oxygen demand of the waste. In the PCR-DGGE molecular analysis, different genomic footprints with oligonucleotides for eubacteria and archeobacteria were found. Biochemical methane potential results proved that banana wastes have the best potential to be used as raw material for methane production. The result of a PCR- DGGE analysis using specific oligonucleotides enabled to identify the behavior of populations of eubacteria and archaeabacteria present during the anaerobic digestion of agroindustrial wastes throughout the process.
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Digestão Anaeróbia/métodos , Gerenciamento de Resíduos/métodos , Metano/biossíntese , Biodegradação Ambiental , Uso de Resíduos Sólidos , Agroindústria/prevenção & controle , Reciclagem/métodos , Análise da Demanda Biológica de Oxigênio/métodos , Resíduos de AlimentosRESUMO
This work presents a techno-economic and environmental assessment of the glucose syrups production from sugarcane bagasse, plantain husk, cassava husk, mango peel, rice husk and corncobs. According to the economic analysis, the corncob had both, the lowest production cost (2.48USD/kg syrup) and the highest yield (0.61kgofsugars/kg of wet agroindustrial waste) due to its high content in cellulose and hemicellulose. This analysis also revealed that a heat integration strategy is necessary since the utilities consumption represent an important factor in the production cost. According to the results, the pretreatment section requires more energy in the syrup production in comparison with the requirements of other sections such as production and sugar concentration. The environmental assessment revealed that the solid wastes such as furfural and hydroxymethylfurfural affected the environmental development of the process for all the agroindustrial wastes, being the rice husk the residue with the lowest environmental impact.
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Produtos Agrícolas/química , Glucose/isolamento & purificação , Meio Ambiente , Glucose/economia , Mangifera/química , Manihot/química , Musaceae/química , Oryza/química , Saccharum/química , Zea mays/químicaRESUMO
Se llevó a cabo la evaluación del cultivo de Pleurotus ostreatus, para determinar el residuo sobre el cual este hongo genera mejor crecimiento y producción. Los sustratos evaluados fueron residuos agroindustriales del departamento de Cundinamarca (capacho de uchuva, cáscara de arveja y tusa de maíz); teniendo como sustrato control el aserrín de roble. Las mezclas a evaluar fueron empacadas en bolsas de 1Kg de volumen de mezcla de sustrato, del cual el 78 por ciento fue el residuo agroindustrial. Se esterilizaron e inocularon con 30g de semillas de Pleurotus ostreatus, adquiridas comercialmente. Se evaluó el tiempo de corrida del micelio, el diámetro de los carpóforos, el número de hongos producidos por bolsa, el peso fresco, la eficiencia biológica y el rendimiento de cada uno de los sustratos trabajados. Finalmente, el mejor sustrato para el crecimiento y producción de Pleurotus ostreatus fue el capacho de uchuva ya que alcanzó una eficiencia biológica de 76.1 por ciento en un período total de producción de 41 días y una rentabilidad de 39.03 Kg/m2 con excelentes características organolépticas, considerándose así un sustrato adecuado y eficiente para el cultivo de este hongo.
The culture of Pleurotus ostreatus was evaluated to determine the best waste on which this mushroom can show the highest growth and production rates.. The substrates evaluated were agroindustrial wastes of theDepartment of Cundinamarca (dry skin of goldenberries (Physalis), skin of pea pods and maize cobs). The control substrate was sawdust of oak. The mixtures evaluated were packed in bags of 1 kg containing 78 % ofagroindustrial waste of the volume of substrate mixture . Mixtures were sterilized and inoculated with 30 g ofseeds of Pleurotus ostreatus obtained commercially. Running time of the mycelium, diameter of fruit bodies,number of fruit bodies produced per bag, fresh weight, biological efficiency, and yield were evaluated on eachof the substrates. Finally, the best substrate for the growth and production of Pleurotus ostreatus was the dryskin of goldenberries (Physalis) with a biological efficiency of 76.1% after a total production period of 41 days and a yield of 39.03 Kg/m2 with excellent organoleptic characteristics, therefore being an adequate and efficient substrate for cultivating this mushroom.
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Pleurotus/crescimento & desenvolvimento , Resíduos/efeitos adversosRESUMO
Biosurfactant production by some bacterial isolates using molasses, milk whey and cassava flour wastewater (manipueira) as substrates was evaluated and compared with the production in conventional medium. Isolates growing in manipueira medium decreased the surface tension around 42%, the highest reduction among all the substrates tested. From the eleven isolates tested, eight were able to decrease the surface tension to levels below 30 mN/m using manipueira as substrate. The isolates LB5a, LB2a, LB262, LBB and LB1a that gave surface tension about 26 mN/m were identified as Bacillus sp. Natural manipueira (high solids content) and decanted manipueira (no solids) were investigated as culture media for biosurfactant production by selected microorganisms. Natural manipueira medium showed minimum surface tension of 28 mN/m (LB5a isolate) whereas for decanted manipueira the lowest value was 26 mN/m (isolate LB2a). Average diameter of growth on manipueira agar was 7.2 cm for isolate LB5a suggesting a high growth capacity on this substrate. Manipueira comprises a potential alternative culture medium for biosurfactant production by the selected isolates.
Alguns isolados bacterianos foram avaliados quanto à capacidade de produção de biossurfatantes a partir de melaço, soro de leite e manipueira como substratos. A produção nestes meios alternativos foi comparada com a produção em meio de cultura convencional. Dentre os meios testados, a manipueira demonstrou a maior percentagem de redução na tensão superficial atingindo valores ao redor de 42%. Dos onze isolados testados, oito foram capazes de diminuir a tensão superficial para níveis inferiores à 30mN/m utilizando manipueira como substrato. Os isolados LB 5a, LB2a, LB262, LBB e LB1a apresentaram tensão superficial em torno de 26 mN/m sendo selecionados e posteriormente identificados como pertencentes ao gênero Bacillus sp. A manipueira natural (alto teor de sólidos) e a manipueira decantada (ausência de sólidos) foram investigadas como meios de cultivo para produção de biossurfatantes pelos microrganismos selecionados. O meio de manipueira natural apresentou tensão superficial minima de 28 mN/m (isolado LB5a) enquanto que o meio de manipueira decantada apresentou tensão superficial mínima de 26 mN/m (isolado LB2a). O diâmetro de crescimento médio do isolado LB5a em ágar manipueira foi de 7.2 cm sugerindo maior capacidade de crescimento neste substrato. A manipueira demonstrou potencial como meio de cultura alternativo para a produção de biossurfatantes pelos isolados selecionados.
RESUMO
Biosurfactant production by some bacterial isolates using molasses, milk whey and cassava flour wastewater (manipueira) as substrates was evaluated and compared with the production in conventional medium. Isolates growing in manipueira medium decreased the surface tension around 42%, the highest reduction among all the substrates tested. From the eleven isolates tested, eight were able to decrease the surface tension to levels below 30 mN/m using manipueira as substrate. The isolates LB5a, LB2a, LB262, LBB and LB1a that gave surface tension about 26 mN/m were identified as Bacillus sp. Natural manipueira (high solids content) and decanted manipueira (no solids) were investigated as culture media for biosurfactant production by selected microorganisms. Natural manipueira medium showed minimum surface tension of 28 mN/m (LB5a isolate) whereas for decanted manipueira the lowest value was 26 mN/m (isolate LB2a). Average diameter of growth on manipueira agar was 7.2 cm for isolate LB5a suggesting a high growth capacity on this substrate. Manipueira comprises a potential alternative culture medium for biosurfactant production by the selected isolates.
Alguns isolados bacterianos foram avaliados quanto à capacidade de produção de biossurfatantes a partir de melaço, soro de leite e manipueira como substratos. A produção nestes meios alternativos foi comparada com a produção em meio de cultura convencional. Dentre os meios testados, a manipueira demonstrou a maior percentagem de redução na tensão superficial atingindo valores ao redor de 42%. Dos onze isolados testados, oito foram capazes de diminuir a tensão superficial para níveis inferiores à 30mN/m utilizando manipueira como substrato. Os isolados LB 5a, LB2a, LB262, LBB e LB1a apresentaram tensão superficial em torno de 26 mN/m sendo selecionados e posteriormente identificados como pertencentes ao gênero Bacillus sp. A manipueira natural (alto teor de sólidos) e a manipueira decantada (ausência de sólidos) foram investigadas como meios de cultivo para produção de biossurfatantes pelos microrganismos selecionados. O meio de manipueira natural apresentou tensão superficial minima de 28 mN/m (isolado LB5a) enquanto que o meio de manipueira decantada apresentou tensão superficial mínima de 26 mN/m (isolado LB2a). O diâmetro de crescimento médio do isolado LB5a em ágar manipueira foi de 7.2 cm sugerindo maior capacidade de crescimento neste substrato. A manipueira demonstrou potencial como meio de cultura alternativo para a produção de biossurfatantes pelos isolados selecionados.