Mutagens in commercial food processing and its microbial transformation.

Mutagens are chemical molecules that have the ability to damage DNA. Mutagens can enter into our body upon consumption of improperly cooked or processed food products such as high temperature or prolonged cooking duration. Mutagens are found in the food products can be classified into N-nitroso derivatives, polycyclic aromatic hydrocarbons, and heterocyclic aromatic amines. Food products with high fat and protein content are more prone to mutagenic formation. Microorganisms were found to be a potent weapon in the fight against various mutagens through biotransformation. Therefore, searching for the microorganisms which have the ability to transform mutagens and the development of techniques for the identification as well as detection of mutagens in food products is much needed. In the future, methods for the identification and detection of these mutagens as well as the identification of new and more potent microorganisms which can transform mutagens into non-mutagens are much needed.

Neural networks and genetic algorithm as robust optimization tools for modeling the microbial production of poly-ß-hydroxybutyrate (PHB) from Brewers' spent grain.

This research work has been carried out to establish the combinatorial impact of various fermentation medium constituents, used for poly-ß hydroxybutyrate (PHB) biosynthesis. Model development was performed with an optimized medium composition that enhanced the biosynthesis of PHB from the biowaste material Brewers' spent grain (BSG). The latter was used as a carbon substrate in submerged fermentation with Bacillus sphaericus NCIM 2478. Three independent variables: BSG, yeast extract (YE), and salt solution concentration (SS) and one dependent variable (amount of PHB produced) were assigned. A total of 35 microbial fermentation trials were conducted by which a nonlinear mathematical relationship was established in terms of neural network model between independent and dependent variables. The resulting artificial neural networks (ANNs) model for this process was further optimized using a global genetic algorithm optimization technique, which predicted the maximum production of PHB (916.31 mg/L) at a concentration of BSG (50.12 g/L), concentration of YE (0.22 g/L), and concentration of SS (24.06%, v/v). The experimental value of the quantity of PHB (concentration ∼916 mg/L) was found to be very close to the value predicted by the ANN-GA model approach.

Primary metabolites from overproducing microbial system using sustainable substrates.

Primary (or secondary) metabolites are produced by animals, plants, or microbial cell systems either intracellularly or extracellularly. Production capabilities of microbial cell systems for many types of primary metabolites have been exploited at a commercial scale. But the high production cost of metabolites is a big challenge for most of the bioprocess industries and commercial production needs to be achieved. This issue can be solved to some extent by screening and developing the engineered microbial systems via reconstruction of the genome-scale metabolic model. The predicted genetic modification is applied for an increased flux in biosynthesis pathways toward the desired product. Wherein the resulting microbial strain is capable of converting a large amount of carbon substrate to the expected product with minimum by-product formation in the optimal operating conditions. Metabolic engineering efforts have also resulted in significant improvement of metabolite yields, depending on the nature of the products, microbial cell factory modification, and the types of substrate used. The objective of this review is to comprehend the state of art for the production of various primary metabolites by microbial strains system, focusing on the selection of efficient strain and genetic or pathway modifications, applied during strain engineering.

Preventive and Therapeutic Potentials of Anthocyanins in Diabetes and Associated Complications.

Diet is an essential factor affecting the development of and risk for diabetes mellitus. In search of preventative and therapeutic strategies, the potential role of certain foods and their bioactive compounds to prevent the pathogenesis associated with metabolic diseases is to be considered. Human consumption of anthocyanins is among the highest of all flavonoids. Epidemiological studies have suggested that the consumption of anthocyanins lowers the risk of diabetes and diabetic complications. Anthocyanins are important natural bioactive pigments responsible for red to blue colour of fruits, leaves, seeds, stems and flowers, which are present in a variety of plant species particularly in berries and cherries. A large number of bioactive anthocyanins, such as cyanidin, malvidin, delphinidin, pelargonidin, peonidin, petunidin and their metabolites have shown multiple biological activities with apparent effects on glucose absorption, glucose uptake, insulin secretion and sensitivity, on the enzymes involved in glucose metabolism, gene expressions, inflammatory mediators, glucose transporters in progression of diabetes and associated complications, such as diabetic retinopathy, nephropathy, neuropathy and diabetic vascular diseases. The versatility of the anthocyanins provides a promising approach for diabetes management than synthetic drugs. Here we summarize the effect of several anthocyanins on many in vitro, in vivo and clinical studies and also reveal the mechanisms which could prevent or reverse the underlying mechanisms of diabetic pathologies including promotion of antioxidant, antihyperlipidemic, anti-inflammatory and anti-apoptotic activities.

Diabetes Mellitus and Male Aging: Pharmacotherapeutics and Clinical Implications.

Andropause or male menopause is defined as androgen decline and onset of hypogonadism in the aging male. Testosterone deficiency in adult male is associated with diabetes mellitus, coronary artery disease, and heart failure. Type 2 diabetic male patients aged above 30 years showed low testosterone levels which is common in diabetic men and had symptoms of hypogonadism. Male sexual dysfunction among diabetic patients can include disorders of libido, ejaculatory problems, and erectile dysfunctions are common among people with diabetes, particularly in older men who had diabetes for years. Older diabetics tend to have both impaired insulin release as well as insulin resistance. There is growing evidence indicating the pathophysiological connections among the mechanisms of oxidative damage by disruption of the oxidative balance, increased levels of enzymatic glycation products in testicular region and glucose transporters, obesity and proinflammatory cytokines in male infertile patients with diabetes. Epidemiological studies suggest that many clinical findings in diabetics are linked to low testosterone levels. This article reviews pathophysiological mechanisms, observational studies, and clinical implications of testosterone therapy in type 2 diabetes mellitus.

Use of Plackett-Burman design for rapid screening of nitrogen and carbon sources for the production of lipase in solid state fermentation by Yarrowia lipolytica from mustard oil cake (Brassica napus)

Mustard oil cake (Brassica napus), the residue obtained after extraction of mustard oil from mustard oil seeds, was investigated for the production of lipase under solid state fermentation (SSF) using the marine yeast Yarrowia lipolytica NCIM 3589. Process parameters such as incubation time, biomass concentration, initial moisture content, carbon source concentration and nitrogen source concentration of the medium were optimized. Screening of ten nitrogen and five carbon sources has been accomplished with the help of Plackett-Burman design. The highest lipase activity of 57.89 units per gram of dry fermented substrate (U/gds) was observed with the substrate of mustard oil cake in four days of fermentation.

Use of Plackett-Burman design for rapid screening of nitrogen and carbon sources for the production of lipase in solid state fermentation by Yarrowia lipolytica from mustard oil cake (Brassica napus).

Mustard oil cake (Brassica napus), the residue obtained after extraction of mustard oil from mustard oil seeds, was investigated for the production of lipase under solid state fermentation (SSF) using the marine yeast Yarrowia lipolytica NCIM 3589. Process parameters such as incubation time, biomass concentration, initial moisture content, carbon source concentration and nitrogen source concentration of the medium were optimized. Screening of ten nitrogen and five carbon sources has been accomplished with the help of Plackett-Burman design. The highest lipase activity of 57.89 units per gram of dry fermented substrate (U/gds) was observed with the substrate of mustard oil cake in four days of fermentation.

Application of statistical experimental designs for the optimization of medium constituents for the production of citric acid from pineapple waste.

Statistical experimental designs were applied for the optimization of medium constituents for citric acid production by Yarrowia lipolytica NCIM 3589 in solid state fermentation (SSF) using pineapple waste as the sole substrate. Using Plackett-Burman design, yeast extract, moisture content of the substrate, KH(2)PO(4) and Na(2)HPO(4) were identified as significant variables which highly influenced citric acid production and these variables were subsequently optimized using a central composite design (CCD). The optimum conditions were found to be yeast extract 0.34 (%w/w), moisture content of the substrate 70.71 (%), KH(2)PO(4) 0.64 (%w/w) and Na(2)HPO(4) 0.69 (%w/w). Citric acid production at these optimum conditions was 202.35 g/kg ds (g citric acid produced/kg of dried pineapple waste as substrate).

Optimization of fermentation parameters to enhance the production of ethanol from palmyra jaggery using Saccharomyces cerevisiae in a batch fermentor.

Application of statistical experimental designs for optimization of fermentation parameters to enhance ethanol production, which is an economical and renewable energy source using Saccharomyces cerevisiae NCIM 3090 from palmyra jaggery, was studied in a batch fermentor. Using Plackett-Burman design, impeller speed, concentrations of CoCl2 and KH2PO4 were identified as significant variables, which highly influenced ethanol production, and these variables were further optimized using a central composite design (CCD). The ethanol production was adequately approximated with a full quadratic equation obtained from three factors and five levels of CCD. Maximum ethanol concentration of 132.56 g/l (16.8% [v/v]) was obtained for an impeller speed of 247.179 ( approximately 250) rev/min, CoCl2 of 0.263 g/l and KH2PO4 of 2.39 g/l. A second-order polynomial regression model was fitted and was found adequate with R 2 of 0.8952. This combined statistical approach enables rapid identification and investigation of significant parameters for improving the ethanol production and could be very useful in optimizing processes.