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Gamma Aminobutyric Acid (GABA) is a bioactive molecule with different physiological roles in the body that inhibits neuronal stimulation and inhibits the delivery of stress-containing messages, has a calming effect and is used to treat diseases. Different has an effective role. In the present study, the possibility of producing this amino acid by Lactococcus lactis NZ1330 was investigated. In order to optimize the fermentation process three levels of dairy sludge (5,10,15%), monosodium glutamate (0, 0.5 and 1%) were selected at 24, 48 and 72 hours after fermentation. The presence of GABA in the culture medium was investigated by thin layer chromatography. Spectrophotometric method was used to quantify the bands present in thin-layer chromatography. Optimization results at 95% significance level showed that the optimum treatment consisted of medium containing 11.2% dairy sludge, 0.7% monosodium glutamate and 70 hours fermentation at 32 ° C and under these conditions, GABA production was ppm. It's 400. Therefore, this combination of media can be used as a suitable substrate for the production of valuable GABA drug and bioactive compounds

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Microbial quality of raw milk is very important in two respects. First, milk consumption itself plays a very significant role in people's food tables and its high microbial load endangers consumer health. Second, if the microbial quality of milk is not suitable, from a technology point of view, milk-derived products will not have a good quality. In this project, which has been carried out in collaboration with Pegah Golestan Company, the separation process (with separators) and double bactofugation was used to reduce microbial load with the aim of reducing milk heating (in order to reduce the nutritional value as a result of heat). Milk samples used for lactic cheese production in Golestan province were examined in 2020 and 2021. After the process, total microbial counting, aerobic and anaerobic spores were counted. The results showed that by using this method, the total microbial load, aerobic and anaerobic spores of the collected milks were reduced to an acceptable level throughout the year without decreasing the microbial quality of the produced cheese during the storage period. On the other hand, the process of separation and bactofugation produces dairy sludge. Normally, dairy sludge is removed every 20 minutes, which was performed in separator and bactofuge1 to 21 minutes to reduce dairy sludge.

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L-glutamate is one of the most abundant amino acids in the body, which plays an important role in various cellular processes and also acts as a precursor of bioactive molecules, which has received much attention due to its medicinal and food applications today, and as an important amino acid. Industrial is produced commercially. L-glutamate is one of the metabolites produced by these bacteria, which is also biologically active. In this research, the production of L-glutamate by three autochthonous lactic acid bacteria (Lactobacillus brevis PML1, Lactobacillus plantarum 1058 and Lactobacillus fermentum 4-17) at three percentage levels of dairy sludge (0, 10, 20%), three levels of soybean meal (0, 2.5, 5%) and three levels of fermentation time (48, 84, 120 hr) were optimized using RSM. TLC was used for qualitative evaluation and HPLC was used for quantitative estimation of L-glutamate production, and then the antimicrobial and antioxidant properties of the fermentation extract were evaluated and compared with the control sample.
 

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Dairy factories produce high volume of sludge from bactofuge and separator. Meantime, global demand for the proteases is increasing. Recently, utilization and conversion of the waste materials into value added product is a sustainable process. The objective of this study was to investigate the potential of bactofuge and separator sludge to produce alkaline protease enzymes. Total viable aerobic and anaerobic counts were determined on Plate Count Agar at 37 and 50^ºC for both types of sludge. Lactobacillus count in MRS Agar plates corresponded to 3.12±0.25 log CFU mL^-1 for sludge of bactofuge and 3.085±0.2 log CFU mL^-1 for sludge of separator. Mold and yeast had population levels of 2.3±0.1 log CFU mL^-1 for bactofuge and 2.08±0.1 log CFU mL^-1 for separator. Proteolytic bacteria were isolated from dairy sludge using Skim Milk Agar media. A clear zone of Skim Milk hydrolysis indicated protease-producing organisms. Different cultural parameters (temperature, pH, thermal shock, and kind of sludge) were optimized for maximal enzyme production. Maximum proteolytic activity was observed at 37^◦C (P< 0.05). Isolated alkaline protease producing Bacilli were identified by Polymerase Chain Reaction (PCR). The species were identified as Bacillus cereus strain zk2, Bacillus sp. cp-h71, Bacillus thuringiensis strain ILBB224, and Bacillus sp. Bac6D₂.
 

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Cheap compounds and wastes of various industries have a set of nutritious compounds that can be used as a culture medium for different strains to produce metabolites with high nutritional value and expensive. Pigment production from microbial source is of interest because it is safe for human health. In this study, with the aim of producing red pigment from the mold Monascus purpureus, firstly, the effect of culture medium factors, potato dextrose broth, yeast extract-sucrose, dairy sludge, soybean meal, sugar cane molasses, whey, temperature, glucose, monosodium glutamate and ammonium sulfate on production biomass (a measure of pigment production) was evaluated through Plackett-Burman design. Then the factors were optimized based on the central square design. Based on the obtained results, dairy sludge base culture medium, glucose, monosodium glutamate and temperature had a positive effect on growth and biomass production (pigment production). With optimization, biomass production in 10% dairy sludge, 0.999% monosodium glutamate, 27°C temperature and 9.83% glucose were obtained with the production of 26.15 g/l of biomass as the optimal state. The results show the capability of dairy sludge waste in the growth of microbial strains and production of significant products.