RESUMO

Bacterial cellulose (BC) is an emerging material for high-end applications due to its biocompatibility and physicochemical characteristics. However, the scale-up production of this material is still expensive, with the culture medium constituting one-third of the total cost. Herein, four different media (yeast nitrogen base, YNB; Murashige and Skoog, MSO; black tea; and NPK fertilizer solution) were compared while using sucrose as an additional carbon source. The yields of BC were best for YNB and fertilizer with 0.37 and 0.34 gBC/gC respectively. These two were then compared using glucose as a carbon source, with improvements in the production of 29% for the fertilizer, while only an 8% increase for YNB was seen; however, as the carbon concentration increased with a fixed N concentration, the yield was lower but the rate of production of BC increased. The obtained BC films were sanitized and showed low molecular weight and all the expected cellulose characteristic FT-IR bands while SEM showed nanofibers around 0.1 µm. Compared to traditional methods for lab-scale production, the use of the fertilizer and the consortium represent benefits compared to traditional lab-scale BC culture methods such as a competitive cost (two times lower) while posing resilience and tolerance to stress conditions given that it is produced by microbial communities and not with a single strain. Additionally, the low molecular weight of the films could be of interest for certain coating formulations.

RESUMO

Abstract Background: Streptococcus agalactiae (GBS), a major cause of neonatal morbidity and mortality, is transmitted from mother to neonate via placenta or during birth. Biofilm formation is an important factor in GBS pathogenesis. This study aimed to determine effects of pH, different culture media and nutritional composition on in vitro biofilm forming ability of GBS isolated from pregnant women. Methods: A total of 30 confirmed isolates of GBS from pregnant women were tested for biofilm formation in Todd Hewitt Broth (THB) at pH 4.5,6 and 7. Ten of these isolates were tested for biofilm formation in growth media THB, brain heart infusion broth, tryptic soy broth, Mueller Hinton broth and nutrient broth. Further they were tested for influence of glucose on biofilm formation using crystal violet and MTT assay. Results: Of 30 GBS isolates strong biofilm formation (SBF) was observed at pH 7 in 56.6 %(n=17) while 36.6%(n=11) isolates showed weak biofilm formation (WBF). At pH 4.5, 43.3% (n=13) were non biofilm formers. In THB without glucose, all 10 isolates were SBF while THB with 1% glucose, 3(30%) isolates were SBF, 5(50%) isolates were moderate biofilm producers and 2(20%) isolates were WBF. Ten isolates tested in 5 types of growth media did not show statistically significant difference in biofilm forming ability. Conclusion: All tested vaginal GBS isolates were able to produce biofilms, maximum biofilm formation of GBS was at pH 7.0. and pH 4.5 is not favorable, thus in normal vaginal pH (3.5 - 4.5), GBS finds it difficult to grow biofilms.

RESUMO

Nitrogen (N) sources have been target in microalgae cultivation studies, considering their nutritional impact on growth and high costs. Here, we have evaluated the growth of Scenedesmus obliquus BR003, applying alternative low-cost culture media containing ammonium and urea, or combinations of both N sources. The culture media were applied for indoor and outdoor cultivation, followed by growth analyses and metabolic characterization. The alternative culture media B4 and L4 supported higher biomass production (1.4 g L-1) compared to BG11 (nitrate-based medium). In addition, the lipid percentage was higher for B4 (ammonium-based culture medium), reaching up to 25% DW. High contents of carbohydrates (60%) and proteins (40%) were also obtained in media with ammonium and urea, respectively. Considering the lower costs of alternative fertilizer-based media, using ammonium and/or urea as N sources, and the high lipid content observed, we suggest these media as viable for large-scale production of S. obliquus.

Assuntos

RESUMO

Abstract During the last years Phytophthora infestans sensu lato (Mont. De Bary) has caused epidemics in Colombia in Andean fruit crops such as Solanum quitoense and Solanum betaceum. Establishment of new or modified experimental procedures to study this pathogen is a mandatory subject for scientists. Twelve isolates of Phytophthora spp. obtained from six different Solanum hosts in Colombia were used to evaluate the effect of five different solid media for growth and ability to produce sporangia and liberate zoospores. Determination of the best media culture and optimal growth temperature were necessary to perform measurements and correlate the provenance of isolates with phenotypic traits. Modifications were made to use ingredients available in local markets on the following media: lime bean agar (LBA), Tree tomato or tree tomato agar (TA), carrot agar (AZ), Rye A modified agar and 32% non-clarified V8 agar. Cardinal temperature determination was performed at 10, 15, 20, and 25 °C. Morphometric traits were measured once the optimal media culture and temperature were defined. Correlation analysis showed that there is a relationship between the host and isolate's preferences for media culture and optimal growth temperature. In addition, the production of characteristic sporangia, sporangiophore and mycelia was related with the media type used and host from which the isolate was collected. In this work useful information was provided to make studies about the biology and development of isolates gathered from cultivated and wild non-traditional hosts.

Resumo Durante os últimos anos Phytophthora infestans sensu lato causou epidemias na Colômbia em lavouras de frutos andinos, como Solanum quitoense e Solanum betaceum. Estabelecimento de procedimentos experimentais novos ou modificados para estudar este patógeno é um assunto obrigatório para os cientistas. Doze isolados de Phytophthora spp. obtidos de seis diferentes hosts Solanum na Colômbia foram usados para avaliar o efeito de cinco diferentes mídias sólidas para o crescimento e a capacidade de produzir esporângios e libertar zoósporos. Determinação da melhor cultura de mídia e temperatura de crescimento ideal foram necessárias para realizar medições e correlacionar a proveniência de isolados com traços fenotípica. Foram feitas modificações para usar os ingredientes disponíveis nos mercados locais nos seguintes meios: ágar do feijão de cal (LBA), tomate da árvore ou ágar do tomate da árvore (TA), ágar da cenoura (AZ), centeio um ágar modificado e 32% de ágar-V8 não-esclarecido. A determinação da temperatura Cardeal foi realizada em 10, 15, 20 e 25 °C. Traços morfométricos foram medidos uma vez que a cultura de mídia ideal e temperatura foram definidos. Análise de correlação mostrou que há uma relação entre o hospedeiro e isolar as preferências para a cultura de mídia e temperatura de crescimento ideal. Além disso, a produção de esporângios característica, esporangióforo e mycelia foi relacionada com o tipo de mídia utilizado e hospedeiros a partir do qual o isolado foi coletado. Neste trabalho foram fornecidas informações úteis para fazer estudos sobre a biologia e o desenvolvimento de isolados recolhidos de hospedeiros não-tradicionais cultivados e selvagens.

Assuntos

RESUMO

During the last years Phytophthora infestans sensu lato (Mont. De Bary) has caused epidemics in Colombia in Andean fruit crops such as Solanum quitoense and Solanum betaceum. Establishment of new or modified experimental procedures to study this pathogen is a mandatory subject for scientists. Twelve isolates of Phytophthora spp. obtained from six different Solanum hosts in Colombia were used to evaluate the effect of five different solid media for growth and ability to produce sporangia and liberate zoospores. Determination of the best media culture and optimal growth temperature were necessary to perform measurements and correlate the provenance of isolates with phenotypic traits. Modifications were made to use ingredients available in local markets on the following media: lime bean agar (LBA), Tree tomato or tree tomato agar (TA), carrot agar (AZ), Rye A modified agar and 32% non-clarified V8 agar. Cardinal temperature determination was performed at 10, 15, 20, and 25 °C. Morphometric traits were measured once the optimal media culture and temperature were defined. Correlation analysis showed that there is a relationship between the host and isolate's preferences for media culture and optimal growth temperature. In addition, the production of characteristic sporangia, sporangiophore and mycelia was related with the media type used and host from which the isolate was collected. In this work useful information was provided to make studies about the biology and development of isolates gathered from cultivated and wild non-traditional hosts.(AU)

Durante os últimos anos Phytophthora infestans sensu lato causou epidemias na Colômbia em lavouras de frutos andinos, como Solanum quitoense e Solanum betaceum. Estabelecimento de procedimentos experimentais novos ou modificados para estudar este patógeno é um assunto obrigatório para os cientistas. Doze isolados de Phytophthora spp. obtidos de seis diferentes hosts Solanum na Colômbia foram usados para avaliar o efeito de cinco diferentes mídias sólidas para o crescimento e a capacidade de produzir esporângios e libertar zoósporos. Determinação da melhor cultura de mídia e temperatura de crescimento ideal foram necessárias para realizar medições e correlacionar a proveniência de isolados com traços fenotípica. Foram feitas modificações para usar os ingredientes disponíveis nos mercados locais nos seguintes meios: ágar do feijão de cal (LBA), tomate da árvore ou ágar do tomate da árvore (TA), ágar da cenoura (AZ), centeio um ágar modificado e 32% de ágar-V8 não-esclarecido. A determinação da temperatura Cardeal foi realizada em 10, 15, 20 e 25 °C. Traços morfométricos foram medidos uma vez que a cultura de mídia ideal e temperatura foram definidos. Análise de correlação mostrou que há uma relação entre o hospedeiro e isolar as preferências para a cultura de mídia e temperatura de crescimento ideal. Além disso, a produção de esporângios característica, esporangióforo e mycelia foi relacionada com o tipo de mídia utilizado e hospedeiros a partir do qual o isolado foi coletado. Neste trabalho foram fornecidas informações úteis para fazer estudos sobre a biologia e o desenvolvimento de isolados recolhidos de hospedeiros não-tradicionais cultivados e selvagens.(AU)

Assuntos

RESUMO

Abstract During the last years Phytophthora infestans sensu lato (Mont. De Bary) has caused epidemics in Colombia in Andean fruit crops such as Solanum quitoense and Solanum betaceum. Establishment of new or modified experimental procedures to study this pathogen is a mandatory subject for scientists. Twelve isolates of Phytophthora spp. obtained from six different Solanum hosts in Colombia were used to evaluate the effect of five different solid media for growth and ability to produce sporangia and liberate zoospores. Determination of the best media culture and optimal growth temperature were necessary to perform measurements and correlate the provenance of isolates with phenotypic traits. Modifications were made to use ingredients available in local markets on the following media: lime bean agar (LBA), Tree tomato or tree tomato agar (TA), carrot agar (AZ), Rye A modified agar and 32% non-clarified V8 agar. Cardinal temperature determination was performed at 10, 15, 20, and 25 °C. Morphometric traits were measured once the optimal media culture and temperature were defined. Correlation analysis showed that there is a relationship between the host and isolates preferences for media culture and optimal growth temperature. In addition, the production of characteristic sporangia, sporangiophore and mycelia was related with the media type used and host from which the isolate was collected. In this work useful information was provided to make studies about the biology and development of isolates gathered from cultivated and wild non-traditional hosts.

Resumo Durante os últimos anos Phytophthora infestans sensu lato causou epidemias na Colômbia em lavouras de frutos andinos, como Solanum quitoense e Solanum betaceum. Estabelecimento de procedimentos experimentais novos ou modificados para estudar este patógeno é um assunto obrigatório para os cientistas. Doze isolados de Phytophthora spp. obtidos de seis diferentes hosts Solanum na Colômbia foram usados para avaliar o efeito de cinco diferentes mídias sólidas para o crescimento e a capacidade de produzir esporângios e libertar zoósporos. Determinação da melhor cultura de mídia e temperatura de crescimento ideal foram necessárias para realizar medições e correlacionar a proveniência de isolados com traços fenotípica. Foram feitas modificações para usar os ingredientes disponíveis nos mercados locais nos seguintes meios: ágar do feijão de cal (LBA), tomate da árvore ou ágar do tomate da árvore (TA), ágar da cenoura (AZ), centeio um ágar modificado e 32% de ágar-V8 não-esclarecido. A determinação da temperatura Cardeal foi realizada em 10, 15, 20 e 25 °C. Traços morfométricos foram medidos uma vez que a cultura de mídia ideal e temperatura foram definidos. Análise de correlação mostrou que há uma relação entre o hospedeiro e isolar as preferências para a cultura de mídia e temperatura de crescimento ideal. Além disso, a produção de esporângios característica, esporangióforo e mycelia foi relacionada com o tipo de mídia utilizado e hospedeiros a partir do qual o isolado foi coletado. Neste trabalho foram fornecidas informações úteis para fazer estudos sobre a biologia e o desenvolvimento de isolados recolhidos de hospedeiros não-tradicionais cultivados e selvagens.

RESUMO

Biochar and hydrochar have been proposed as novel materials for providing soilless growth media. However, much more knowledge is required before reliable advice can be given on the use of these materials for this purpose. Depending on the material and the technology applied (pyrolysis or hydrothermal carbonization), phytotoxicity and greenhouse gas emissions have been found for certain chars. In this study, our aim was to assess the feasibility of three chars as substrate constituents. We compared two biochars, one from forest waste and the other from olive mill waste, and a hydrochar from forest waste. We studied how chars affected substrate characteristics, plant performance, water economy and respiratory CO2 emission. Substrates containing biochar from forest waste showed the best characteristics, with good air/water relationships and adequate electrical conductivity. Those with biochar from olive mill waste were highly saline and, consequently, low quality. The substrates with hydrochar retained too much water and were poorly aerated, presenting high CO2 concentrations due to high respiratory activity. Plants performed well only when grown in substrates containing a maximum of 25 % biochar from forest waste or hydrochar. After analyzing the char characteristics, we concluded that biochar from forest waste could be safely used as a substrate constituent and is environmentally friendly when applied due to its low salinity and low CO2 emission. However, biochar from olive mill waste and hydrochar need to be improved before they can be used as substrate constituents.(AU)

Assuntos

RESUMO

ABSTRACT Biochar and hydrochar have been proposed as novel materials for providing soilless growth media. However, much more knowledge is required before reliable advice can be given on the use of these materials for this purpose. Depending on the material and the technology applied (pyrolysis or hydrothermal carbonization), phytotoxicity and greenhouse gas emissions have been found for certain chars. In this study, our aim was to assess the feasibility of three chars as substrate constituents. We compared two biochars, one from forest waste and the other from olive mill waste, and a hydrochar from forest waste. We studied how chars affected substrate characteristics, plant performance, water economy and respiratory CO2 emission. Substrates containing biochar from forest waste showed the best characteristics, with good air/water relationships and adequate electrical conductivity. Those with biochar from olive mill waste were highly saline and, consequently, low quality. The substrates with hydrochar retained too much water and were poorly aerated, presenting high CO2 concentrations due to high respiratory activity. Plants performed well only when grown in substrates containing a maximum of 25 % biochar from forest waste or hydrochar. After analyzing the char characteristics, we concluded that biochar from forest waste could be safely used as a substrate constituent and is environmentally friendly when applied due to its low salinity and low CO2 emission. However, biochar from olive mill waste and hydrochar need to be improved before they can be used as substrate constituents.

RESUMO

ABSTRACT Biochar and hydrochar have been proposed as novel materials for providing soilless growth media. However, much more knowledge is required before reliable advice can be given on the use of these materials for this purpose. Depending on the material and the technology applied (pyrolysis or hydrothermal carbonization), phytotoxicity and greenhouse gas emissions have been found for certain chars. In this study, our aim was to assess the feasibility of three chars as substrate constituents. We compared two biochars, one from forest waste and the other from olive mill waste, and a hydrochar from forest waste. We studied how chars affected substrate characteristics, plant performance, water economy and respiratory CO2 emission. Substrates containing biochar from forest waste showed the best characteristics, with good air/water relationships and adequate electrical conductivity. Those with biochar from olive mill waste were highly saline and, consequently, low quality. The substrates with hydrochar retained too much water and were poorly aerated, presenting high CO2 concentrations due to high respiratory activity. Plants performed well only when grown in substrates containing a maximum of 25 % biochar from forest waste or hydrochar. After analyzing the char characteristics, we concluded that biochar from forest waste could be safely used as a substrate constituent and is environmentally friendly when applied due to its low salinity and low CO2 emission. However, biochar from olive mill waste and hydrochar need to be improved before they can be used as substrate constituents.

RESUMO

Abstract During the last years Phytophthora infestans sensu lato (Mont. De Bary) has caused epidemics in Colombia in Andean fruit crops such as Solanum quitoense and Solanum betaceum. Establishment of new or modified experimental procedures to study this pathogen is a mandatory subject for scientists. Twelve isolates of Phytophthora spp. obtained from six different Solanum hosts in Colombia were used to evaluate the effect of five different solid media for growth and ability to produce sporangia and liberate zoospores. Determination of the best media culture and optimal growth temperature were necessary to perform measurements and correlate the provenance of isolates with phenotypic traits. Modifications were made to use ingredients available in local markets on the following media: lime bean agar (LBA), Tree tomato or tree tomato agar (TA), carrot agar (AZ), Rye A modified agar and 32% non-clarified V8 agar. Cardinal temperature determination was performed at 10, 15, 20, and 25 °C. Morphometric traits were measured once the optimal media culture and temperature were defined. Correlation analysis showed that there is a relationship between the host and isolates preferences for media culture and optimal growth temperature. In addition, the production of characteristic sporangia, sporangiophore and mycelia was related with the media type used and host from which the isolate was collected. In this work useful information was provided to make studies about the biology and development of isolates gathered from cultivated and wild non-traditional hosts.

Resumo Durante os últimos anos Phytophthora infestans sensu lato causou epidemias na Colômbia em lavouras de frutos andinos, como Solanum quitoense e Solanum betaceum. Estabelecimento de procedimentos experimentais novos ou modificados para estudar este patógeno é um assunto obrigatório para os cientistas. Doze isolados de Phytophthora spp. obtidos de seis diferentes hosts Solanum na Colômbia foram usados para avaliar o efeito de cinco diferentes mídias sólidas para o crescimento e a capacidade de produzir esporângios e libertar zoósporos. Determinação da melhor cultura de mídia e temperatura de crescimento ideal foram necessárias para realizar medições e correlacionar a proveniência de isolados com traços fenotípica. Foram feitas modificações para usar os ingredientes disponíveis nos mercados locais nos seguintes meios: ágar do feijão de cal (LBA), tomate da árvore ou ágar do tomate da árvore (TA), ágar da cenoura (AZ), centeio um ágar modificado e 32% de ágar-V8 não-esclarecido. A determinação da temperatura Cardeal foi realizada em 10, 15, 20 e 25 °C. Traços morfométricos foram medidos uma vez que a cultura de mídia ideal e temperatura foram definidos. Análise de correlação mostrou que há uma relação entre o hospedeiro e isolar as preferências para a cultura de mídia e temperatura de crescimento ideal. Além disso, a produção de esporângios característica, esporangióforo e mycelia foi relacionada com o tipo de mídia utilizado e hospedeiros a partir do qual o isolado foi coletado. Neste trabalho foram fornecidas informações úteis para fazer estudos sobre a biologia e o desenvolvimento de isolados recolhidos de hospedeiros não-tradicionais cultivados e selvagens.

RESUMO

The objective of this study was to isolate LAB from dairy, meat products and agro-industrial wastes and to investigate their antagonist activity. A total of 141 isolates were screened for the inhibitory effect on ten indicator strains in the agar spot test. Results showed that strain LBbb0141 contained antimicrobial compound with wide spectrum that inhibited the growth of ten indicator Gram-positive and Gram-negative strains. The bacteriocin activity attained its maximum value using the MRS agar at initial pH 7.5 and 30°C incubation temperature.