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Essential amino acid, tryptophan which intake from food plays a critical role in numerous metabolic functions, exhibiting extensive biological functions and applications. Tryptophan is beneficial for the food sector by enhancing nutritional content and promoting the development of functional foods. A putative gene encoding tryptophan synthase was the first identified in Sphingobacterium soilsilvae Em02, a cellulosic bacterium making it inherently more environmentally friendly. The gene was cloned and expressed in exogenous host Escherichia coli, to elucidate its function. The recombinant tryptophan synthase with a molecular weight 42 KDa was expressed in soluble component. The enzymatic activity to tryptophan synthase in vivo was assessed using indole and L-serine and purified tryptophan synthase. The optimum enzymatic activity for tryptophan synthase was recorded at 50 ºC and pH 7.0, which was improved in the presence of metal ions Mg2+, Sr2+ and Mn2+, whereas Cu2+, Zn2+ and Co2+ proved to be inhibitory. Using site-directed mutagenesis, the consensus pattern HK-S-[GGGSN]-E-S in the tryptophan synthase was demonstrated with K100Q, S202A, G246A, E361A and S385A as the active sites. Tryptophan synthase has been demonstrated to possess the defining characteristics of the ß-subunits. The tryptophan synthase may eventually be useful for tryptophan production on a larger scale. Its diverse applications highlight the potential for improving both the quality and health benefits of food products, making it an essential component in advancing food science and technology.

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In this study, a gene encoding for acetylxylan esterase was cloned and expressed in E. coli. A single uniform band with molecular weight of 31.2 kDa was observed in SDS-PAGE electrophoresis. Served as the substrate, p-nitrophenol butyrate was employed to detect the recombinant enzyme activity. It exhibited activity at a wide temperature range (30-100 °C) and pH (5.0-9.0) with the optimal temperature of 70 °C and pH 8.0. Acetylxylan esterase showed two substrates' specificities with the highest Vmax of 177.2 U/mg and Km of 20.98 mM against p-nitrophenol butyrate. Meanwhile, the Vmax of p-nitrophenol acetate was 137.0 U/mg and Km 12.16 mM. The acetic acid yield of 0.39 g/g was obtained (70 °C and pH 8.0) from wheat bran pretreated using amylase and papain. This study showed the highest yield up to date and developed a promising strategy for acetic acid production using wheat bran.

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High-value chemical production from natural lignocellulose transformation is a reliable waste utilization approach. A gene encoding cold-adapted carboxylesterase in Arthrobacter soli Em07 was identified. The gene was cloned and expressed in Escherichia coli to obtain a carboxylesterase enzyme with a molecular weight of 37.2 KDa. The activity of the enzyme was determined using α-naphthyl acetate as substrate. Results showed that the optimum enzyme activity of carboxylesterase was at 10 °C and pH 7.0. It was also found that the enzyme could degrade 20 mg enzymatic pretreated de-starched wheat bran (DSWB) to produce 235.8 µg of ferulic acid under the same conditions, which was 5.6 times more than the control. Compared to the chemical strategy, enzymatic pretreatment is advantageous because it is environmentally friendly, and the by-products can be easily treated. Therefore, this strategy provides an effective method for high-value utilization of biomass waste in agriculture and industry.

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The development of biohydrogen as an alternative energy source has had great economic and environmental benefits. Hydrogen production from microalgae is considered a clean and sustainable energy production method that can both alleviate fuel shortages and recycle waste. Although algal hydrogen production has low energy consumption and requires only simple pretreatment, it has not been commercialized because of low product yields. To increase microalgal biohydrogen production several technologies have been developed, although they struggle with the oxygen sensitivity of the hydrogenases responsible for hydrogen production and the complexity of the metabolic network. In this review, several genetic and metabolic engineering studies on enhancing microalgal biohydrogen production are discussed, and the economic feasibility and future direction of microalgal biohydrogen commercialization are also proposed.

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The aim of this work is to study a bifunctional endoglucanase/carboxylesterase in Sphingobacterium soilsilvae Em02 and express it in soluble form in engineered Escherichia coli. The molecular weight of the recombinant protein of the bifunctional enzyme was 41 KDa. This research also determined the enzymatic activities of the bifunctional enzymes using microcrystalline cellulose and p-nitrophenyl butyrate as substrates and found 40 °C as the optimum temperature for their enzymatic activities. The optimal pH in dual function was 6.0 for endoglucanase and 7.0 for carboxylesterase. The bifunctional enzyme also exhibited enzymatic activities on the natural biomass by generating up to 3.94 mg of glucose and 49.4 µg of ferulic acid from 20 mg of destarched wheat bran. This indicates the broad application prospects of the bifunctional enzyme in agriculture and industry.

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Bioactive molecules of microbial origin are finding increasing biotechnological applications. Their sources range from the terrestrial, marine, and endophytic to the human microbiome. These biomolecules have unique chemical structures and related groups, which enable them to improve the efficiency of the bioprocesses. This review focuses on the applications of biomolecules in bioremediation, agriculture, food, pharmaceutical industries, and human health.

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With a continuously increasing human population is an increasing global demand for food. People in countries with a higher socioeconomic status tend to switch their preferences from grains to meat and high-value foods. Their preference for chicken as a source of protein has grown by 70% over the last three decades. Many studies have shown the role of feed in regulating the animal gut microbiome and its impact on host health. The microbiome absorbs nutrients, digests foods, induces a mucosal immune response, maintains homeostasis, and regulates bioactive metabolites. These metabolic activities are influenced by the microbiota and diet. An imbalance in microbiota affects host physiology and progressively causes disorders and diseases. With the use of antibiotics, a shift from dysbiosis with a higher density of pathogens to homeostasis can occur. However, the progressive use of higher doses of antibiotics proved harmful and resulted in the emergence of multidrug-resistant microbes. As a result, the use of antibiotics as feed additives has been banned. Researchers, regulatory authorities, and managers in the poultry industry have assessed the challenges associated with these restrictions. Research has sought to identify alternatives to antibiotic growth promoters for poultry that do not have any adverse effects. Modulating the host intestinal microbiome by regulating dietary factors is much easier than manipulating host genetics. Research efforts have led to the identification of feed additives, including bacteriocins, immunostimulants, organic acids, phytogenics, prebiotics, probiotics, phytoncides, and bacteriophages. In contrast to focusing on one or more of these alternative bioadditives, an improved feed conversion ratio with enhanced poultry products is possible by employing a combination of feed additives. This article may be helpful in future research towards developing a sustainable poultry industry through the use of the proposed alternatives.

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Lignocellulose waste was served as promising raw material for bioethanol production. Bioethanol was considered to be a potential alternative energy to take the place of fossil fuels. Lignocellulosic biomass synthesized by plants is regenerative, sufficient and cheap source for bioethanol production. The biotransformation of lignocellulose could exhibit dual significance-reduction of pollution and obtaining of energy. Some strategies are being developing and increasing the utilization of lignocellulose waste to produce ethanol. New technology of bioethanol production from natural lignocellulosic biomass is required. In this paper, the progress in genetic manipulation strategies including gene editing and synthetic genomics for the transformation from lignocellulose to ethanol was reviewed. At last, the application prospect of bioethanol was introduced.

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BACKGROUND: The prognosis value of paraspinal muscle degeneration on clinical outcomes has been revealed. However no study has investigated the effect of the fat infiltration (FI) of paraspinal muscles on bone nonunion after posterior lumbar interbody fusion (PLIF). METHODS: Three hundred fifty-one patients undergoing PLIF for lumbar spinal stenosis with 1-year follow-up were retrospectively identified. Patients were categorized into bone union (n = 301) and bone nonunion (n = 50) groups based on dynamic X-ray at 1-year follow-up. The relative total cross-sectional area (rTCSA) and FI of multifidus (MF) and erector spinae (ES), and the relative functional CSA (rFCSA) of psoas major (PS) were measured on preoperative magnetic resonance imaging. RESULTS: The nonunion group had a significantly higher MF FI and a higher ES FI and a smaller MF rTCSA than the union group (p = 0.001, 0.038, 0.026, respectively). Binary logistic regression revealed that MF FI (p = 0.029, odds ratio [OR] = 1.04), lumbosacral fusion (p = 0.026, OR = 2193) and length of fusion (p = 0.001, OR = 1.99) were independent factors of bone nonunion. In subgroup analysis, in one or two-level fusion group, the patients with nonunion had a higher MF FI and a higher ES FI than those of the patients with union (all p < 0.05). Similarly, in lumbosacral fusion group, the patients with nonunion had a higher MF FI and a higher ES FI than those of the patients with union (all p < 0.05). The logistic regressions showed that MF FI remained an independent factor of bone nonunion both in the patients with one or two-level fusion (p = 0.003, OR = 1.074) and in the patients with lumbosacral fusion (p = 0.006, OR = 1.073). CONCLUSIONS: Higher fatty degeneration was strongly associated with bone nonunion after PLIF. Surgeons should pay attention to the FI of paraspinal muscles when performing posterior surgery for patients, especially those who need short-segment fusion or to extend fusion to S1.

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BACKGROUND: To investigate the difference of paraspinal muscles in patients with normal bone density, osteopenia and osteoporosis. METHODS: Patients undergoing surgery for lumbar spinal stenosis were included. Thirty-eight patients with osteoporosis were matched to patients with osteopenia and patients with normal bone density in a 1:1 manner according to WHO criteria. Dual-energy X-ray absorptiometry (DXA) scans and lumbar CT were performed preoperatively to measure the BMD of lumbar, femur and hip and HU values of L1-L4 respectively. The relative total cross-sectional area (rTCSA) and fat infiltration (FI) of multifidus (MF) and erector spinae (ES), and the relative functional CSA (rFCSA) of psoas major (PS) were measured at L4-5 and L5-S level on preoperative MRI. RESULTS: Osteoporotic patients showed lower BMI, higher MF FI and higher ES FI when compared with normal bone density group (25.57 ± 3.71 vs 27.46 ± 3.11; 0.38 ± 0.1 vs 0.32 ± 0.08; 0.33 ± 0.1 vs 0.28 ± 0.08; all adjusted p < 0.05). Both the MF FI and ES FI were significantly correlated with lumbar T-score (r = - 0.223, p < 0.05; r = - 0.208, p < 0.05) and the averaged lumbar HU value (r = - 0.305, p < 0.01; r = - 0.239, p < 0.05). CONCLUSIONS: Osteoporosis and paraspinal muscle degeneration might interact with each other and coexist in patients with degenerative lumbar diseases. It is recommended that the paraspinal muscle degeneration should be considered simultaneously when finding a patient with low bone mass before surgery.

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The human gastrointestinal tract (GIT) is a well-recognized hub of microbial activities. The microbiota harboring the mucus layer of the GIT act as a defense against noxious substances, and pathogens including Clostridium difficile, Enterococcus faecium, Escherichia coli, Salmonella Typhimurium. Toxins, pathogens, and antibiotics perturb the commensal floral composition within the GIT. Imbalanced gut microbiota leads to dysbiosis, manifested as diseases ranging from obesity, diabetes, and cancer to reduced lifespan. Among the bacteria present in the gut microbiome, the most beneficial are those representing Firmicutes and Bacteroidetes. Recent studies have revealed the emergence of a novel biotherapeutic agent, Akkermansia, which is instrumental in regaining eubiosis and conferring various health benefits.

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Presently, fossil fuels are extensively employed as major sources of energy, and their uses are considered unsustainable due to emissions of obnoxious gases on the burning of fossil fuels, which can lead to severe environmental complications, including human health. To tackle these issues, various processes are developing to waste as a feed to generate eco-friendly fuels. The biological production of fuels is considered to be more beneficial than physicochemical methods due to their environmentally friendly nature, high rate of conversion at ambient physiological conditions, and less energy-intensive. Among various biofuels, hydrogen (H2) is considered as a wonderful due to high calorific value and generate water molecule as end product on the burning. The H2 production from biowaste is demonstrated, and agri-food waste can be potentially used as a feedstock due to their high biodegradability over lignocellulosic-based biomass. Still, the H2 production is uneconomical from biowaste in fuel competing market because of low yields and increased capital and operational expenses. Anaerobic digestion is widely used for waste management and the generation of value-added products. This article is highlighting the valorization of agri-food waste to biofuels in single (H2) and two-stage bioprocesses of H2 and CH4 production.

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PURPOSE: Numerous studies have applied a variety of methods to assess paraspinal muscle degeneration. However, the methodological differences in imaging evaluation may lead to imprecise or inconsistent results. This article aimed to provide a pragmatic summary review of the current imaging modalities, measurement protocols, and imaging parameters in the evaluation of paraspinal muscle fat infiltration (FI) in MRI studies. METHODS: Web of Science, EMBASE, and PubMed were searched from January 2005 to March 2020 to identify studies that examined the FI of paraspinal muscles on MRI among patients with lumbar degenerative diseases. RESULTS: Intramyocellular lipids measured by magnetic resonance spectroscopy and FI measured by chemical-shift MRI were both correlated to low back pain and several degenerative lumbar diseases, whereas results on the relationship between FI and degenerative lumbar pathologies using conventional MRI were conflicting. Multi-segment measurement of FI at the lesion segment and adjacent segments could be a prognostic indicator for lumbar surgery. Most studies adopted the center of the intervertebral disc or endplate as the level of slice to evaluate the FI. Compared with visual semiquantitative assessment, quantitative parameters appeared to be precise for eliminating individual or modality differences. It has been demonstrated that fat CSA/total CSA (based on area) and muscle-fat index (based on signal intensity) as quantitative FI parameters are associated with multiple lumbar diseases and clinical outcomes after surgery. CONCLUSION: Having a good command of the methodology of paraspinal muscle FI on MRI was effective for diagnosis and prognosis in clinical practice.

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Microbes operate their metabolic activities at a unicellular level. However, it has been revealed that a few metabolic activities only prove beneficial to microbes if operated at high cell densities. These cell density-dependent activities termed quorum sensing (QS) operate through specific chemical signals. In Gram-negative bacteria, the most widely reported QS signals are acylhomoserine lactones. In contrast, a novel QS-like system has been elucidated, regulating communication between microbes and plants through strigolactones. These systems regulate bioprocesses, which affect the health of plants, animals, and human beings. This mini-review presents recent developments in the QS and QS-like signal molecules in promoting plant health.

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The active sludge treating propylene oxide saponification wastewater has heavy salt concentration and is hard to treat. The integration of the residual sludge treatment with polyhydroxyalkanoates (PHA) production may provide an economic and environment friendly solution. PHA production was therefore studied in two sequencing biological reactors with effective volume of 30 L using the active sludge. The two reactors, named as SBR-I and SBR-II, were fed with acetic acid, and a mixture of acetic acid and propionic acid respectively. PHA was obtained with a yield of 9.257 g/L in SBR-II. Also, the proportion of 3-hydroxyvalarate was enhanced from 5% to 30% in comparison to SBR-I (5.471 g/L). Illumina MiSeq and Pacific Biosciences sequencing platforms were used to evaluate the community structure, which revealed that the bacterial genera showed a high degree of diversity in the PHA accumulating microbial community. Azoarcus was the most dominant PHA accumulating microorganism after acclimation.

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A versatile ionic crosslink lithography (ICL) approach is reported to achieve geometry transitions of strong polyvinyl alcohol/sodium alginate (PVA/SA) hydrogels in a controllable and programmable manner. Specifically, localized PVA/SA and PVA/SA/Fe3+ hydrogel domains of significantly different swellabilities (i.e., in-plane gradient) are created by patterning and selective ionic crosslinking of one single type of PVA/SA hydrogel. A simple two-step sequential pre- and free-swelling, or each alone, directs the patterned, inhomogeneous hydrogel to transform in various programmable and quasi-quantitative ways through local bulging and/or global buckling. All types of shape changing are reversible and repeatable due to the reversible nature of ionic coordination in the hydrogel networks. The flexibility and versatility of 3D printing is also demonstrated in creating through-thickness gradient in PVA and PVA/SA hydrogel assemblies with similar morphing capability. The ICL approach developed in this work may help shed some light on developing strong and shape morphing hydrogels as soft sensors and actuators and for potentially biomimetic transformations. The ICL approach may also be transferable to fabrication of many other types of hydrogel materials for similar applications.

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In this study, chemoenzymatic conversion of Sorghum durra stalk (SDS) into furoic acid was developed by a sequential microwave-assisted solid acid conversion and immobilized whole-cells biocatalysis method. Dry dewaxed SDS (75 g/L) was catalyzed into furfural at 57.8% yield with heterogeneous Sn-argil (2.0 wt% dosage) in n-ethyl butyrate-H2O (1:1, v:v) biphasic system using a microwave (600 W) for 10 min at 180 °C. In this biphasic media (pH 6.5), SDS-derived furfural (125.0 mM) was biologically oxidized to furoic acid by immobilized Brevibacterium lutescens cells harboring furfural-oxidizing activity at 30 °C, and furfural was wholly transformed to furoic acid within 24 h. Finally, the recovery and reuse of the Sn-argil catalyst and immobilized biocatalysts were conducted for synthesizing furoic acid from SDS in the biphasic system. This chemoenzymatic route can be attractive for furoic acid production.

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A putative glutamine synthetase (GS) was detected in a psychrophilic bacterium, Cryobacterium soli GCJ02. For gaining greater insight into its functioning, the gene was cloned and expressed in a heterologous host, Escherichia coli. The monomer enzyme with a molecular weight of 53.03 kDa was expressed primarily in cytosolic compartment. The enzyme activity was detected using glutamate and ATP. The optimum conditions of its biosynthesis were observed to be 60 °C and pH value 7.5. Its thermostability was relatively high with a half-life of 50 min at 40 °C. GS activity was enhanced in the presence of metal ions such as Mg2+ and Mn2+, whereas Fe2+, Cu2+ and Ca2+ proved inhibitory. The consensus pattern [EXE]-D-KP-[XGXGXH] in the GS lies between residues 132 and 272. The catalytic active sites consisting of EAE and NGSGMH were verified by site-directed mutagenesis. Based on the analysis of the consensus pattern, the GS/glutamate synthase cycle of C. soli GCJ02 is expected to contribute to the GS synthesic activity.

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The green synthesis of the flavor esters, n-propyl acetate, isobutyl acetate and isoamyl acetate had the advantages over the chemical synthesis. The esterase from Candida parapsilosis could transform n-propanol, isobutanol and isoamyl alcohol into n-propyl acetate, isobutyl acetate and isoamyl acetate, respectively. The esterase was expressed in Saccharomyces cerevisiae. At 30 °C for 1 d, the concentration of n-propyl acetate, isobutyl acetate and isoamyl acetate synthesized by the esterase expressed in Saccharomyces cerevisiae was 24.6 mg/100 mL, 8.3 mg/100 mL, 5.6 mg/100 mL, respectively. Expression of the esterase has a practical significance for flavor ester synthesis by green biochemical process.

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The main aim of this work was to firstly develop a selective oxidation approach for biologically converting 5-hydroxymethylfurfural and furfural into the corresponding furan-based carboxylic acids with recombinant Escherichia coli HMFOMUT. Whole-cells of this recombinant strain harbored good biocatalytic activity in a narrow pH range (pH 6.5-7.0), which had high tolerance toward furfural (up to 50 mM) and 5-hydroxymethylfurfural (up to 150 mM), well-known potential inhibitors against microorganisms. 5-Hydroxymethyl-2-furancarboxylic acid and furoic acid could be obtained at 96.9% and 100% yield from 5-hydroxymethylfurfural (150 mM) and furfural (50 mM) at 30 °C and pH 7.0. The improved substrate tolerance of Escherichia coli HMFOMUT is gaining a great interest to synthesize value-added furan-based carboxylic acids, which has potential industrial applications.

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