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Levan is a highly water-soluble biopolymer that has extensive applications in the pharmaceutical, personal care, food, and industrial fields. Lactobacillus fermentum SHN1 was isolated from milk and dairy products as an exopolysaccharide (levan) producer and identified according to morphological, biochemical tests and using the 16S rRNA gene sequencing. The sequence alignment in the gene bank indicated that the isolate has a high percentage of similarity (100%) to the recovered sequence of Lactobacillus fermentum isolate. The produced biopolymer was characterized as levan by FTIR, ¹H-NMR, and 13C-NMR spectroscopy. The effect of various nutritional and physical factors including pH, carbon source, sucrose concentration, nitrogen source, inoculum size, and incubation period, on the synthesis of levan by L. fermentum SHN1 was studied. The findings indicated that the optimal carbon source for the production of levan was 100 g/L sucrose, yielded of 25.95 g/L. Additionally, a combination of peptone + yeast extract at a ratio of 2:0.5 was identified as the most effective nitrogen source for levan production, giving in a yield of 24.21 g/L. L. fermentum SHN1 produces the greatest quantity of levan, 23.89 g/L, under a pH of 6.5 and an inoculum size of 1%, resulting in a yield of 25 g/L. The most favorable period for incubation was 48 hours, resulting in a production yield of 24.87 g/L. [ABSTRACT FROM AUTHOR]

An exopolysaccharide (EPS)-producing soil bacterium was isolated and characterized using 16S rRNA as Bacillus sp. EPS003. EPS was precipitated using ethanol and % composition of total carbohydrate, and protein was determined. Monosaccharide composition was identified using thin layer chromatography (TLC), and it was found to be a levan. Fourier transform infrared (FTIR) spectrum revealed the peaks for carboxyl, hydroxyl, and amide functional groups. 1H nuclear magnetic resonance (NMR) spectrum further confirmed the presence of fructose monomer. Field emission scanning electron microscopic images (FE-SEM) revealed porous and amorphous characteristics of EPS which was further confirmed with broad peaks in X-ray diffraction (XRD) spectrum. Elemental composition was determined using energy-dispersive X-ray analysis (EDAX). Thermogravimetric analysis (TGA) of EPS resulted in a residual mass of 33.81% at 548 °C indicating high thermal stability. In addition, solubility index and water-holding capacity of EPS were found to be 56% and 264%, respectively, making EPS suitable for various applications. Further, antioxidant potential of EPS was studied using hydroxyl and DPPH radical scavenging assays. In vitro cytotoxicity assessment using L929 cells and SK-MEL-3 cell lines clearly indicated that the EPS produced by the novel isolate Bacillus sp. EPS003 could serve as a potential anticancer agent. [ABSTRACT FROM AUTHOR]

Bacteria play a crucial role in almost all fields of biotechnology. Among them, industrial and medical biotechnology are the fields that are highly dependent on bacteria and their metabolites. Thus, bacterial growth media with correct ingredients and composition is crucial. This study was performed to prepare a protein hydrolysate from the waste chicken feathers using a true keratinolytic bacterium, Bacillus pumilus AR57 and to further investigate the usability of protein hydrolysate as a peptone source for bacterial cultivation and metabolite production. Feather degrading capability of B. pumilus AR57 was improved by serial sub-culturing in the presence of increased feather concentration. The chicken feather protein hydrolysate (CFPH) was collected from a modified minimal medium supplemented with 2% (w/v) feather and its biochemical characterization were studied in detail (Protein concentration: 1.127 mg/ml; functional group and amino acid composition by FTIR and HPLC analysis). In the sequential nutrient depletion study, CFPH in combination with nutrient broth showed promising results by shortening the doubling time of the test bacteria during their initial log phase. Even though, the test strains suffered a sudden nutrient shift (feast-to-famine) the overall growth was not affected much except with a little frameshift in the growth kinetics. Similarly, when compared with commercial peptones, CFPH was found to be superior in the growth performances (CFU/ml and biomass). The growth resumption of bacterial strains from famine-to-feast showed a tremendous revival rate when compared to feast-to-feast. The amino acid composition and elemental analysis of CFPH were found to be enriched with essential amino acids and micro, macronutrients. CFPH was formulated as a whole production medium for keratinase. This results in faster feather degradation (22 h) and higher keratinase activity. Taken together, the present study emphasizes that Feaptone, an unprocessed CFPH as an effective alternative source of peptone which can be further formulated as a commercial media supplement. [ABSTRACT FROM AUTHOR]