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Biosurfactants are amphiphilic compounds produced by bacteria either extracellularly or as a part of the cell membrane. Biosurfactants have had a profound impact on medical and pharmaceutical biotechnology. In our previous work, we isolated a new biosurfactant produced by Acinetobacter indicus M6 which reduces the surface tension of water from 72.0 to 39.8 mN/m and which showed thermophilic, halophytic and acidophilic stability. The chemical nature was found to be a class of glycolipoprotein. Here, our research presents the extracted biosurfactant’s anti-proliferative activity against lung cancer cells (A549), and anti-microbial and anti-biofilm activity against MRSA. The anti-tumour activity of biosurfactant against lung cancer cells was evaluated in terms of cell viability at different concentrations. The results showed a decrease in the percentage of lung cancer viable cells with increasing biosurfactant concentrations and incubation time, with a significant decrease being observed at 200 µg/ml concentration leading to cell proliferation inhibition at G1 phase. Treatment of biofilms for seven days at 500 µg/ml resulted in up to 82.5% biofilm disruption. Keywords: Biosurfactant, Acinetobacter indicus M6, Cell viability, Anti-proliferative activity, Anti-biofilm activity

In the present investigation, a low-cost fermentation medium was designed to achieve the maximum production of lactase from the Bacillus sp. VUVD101 strain through the screening of different nutritional and physical variables, using the Plackett-Burman design. Fourteen variables of the fermentation process were selected: incubation time, temperature, pH, RPM, DO, inoculum size, inoculum age, MgSO4, l-Cysteine, KH2PO4, CaCl2, K2PHO4, corn steep liquor and lactose. The selected variables were evaluated through statistical analysis, based on their significance, coefficient value and standard effect plot. The results suggested that six variables, namely, corn steep liquor, lactose, MgSO4, temperature, pH and RPM, had influence with high confidence levels, while the remaining eight variables did not show a significant effect on production. The analysis of the variance value R2 (0.96) also showed the model used for prediction to be significant (p less than 0.05). The plot for the standard effect for each component and its traits provided accurate data by which to select well-suited variables for further optimization. In comparison with the basal medium, 68% higher enzyme activity was achieved from the model of the optimized medium, and lactase activity was found to be 18.31 U/ml. Keywords: Lactase, Variables, Nutrient sources, Plackett-Burman design

CRISPR genome editing utilizes Cas9 nuclease and single guide RNA (sgRNA), which directs the nuclease to a specific site in the genome and makes a double-stranded break (DSB). Design of sgRNA for CRISPR-Cas targeting, and to promote CRISPR adaptation, uses a regulatory mechanism that ensures maximum CRISPR-Cas9 system functions when a bacterial population is at highest risk of phage infection. Acinetobacter baumannii is the most regularly identified gram-negative bacterium infecting patients. Recent reports have demonstrated that the extent of diseases caused by A. baumannii is expanding and, in a few cases, now surpasses the quantity of infections caused by P. aeruginosa. Most Acinetobacter strains possess biofilm-forming ability, which plays a major role in virulence and drug resistance. Biofilm bacteria use quorum sensing, a cell-to-cell communication process, to activate gene expression. Many genes are involved in biofilm formation and the mechanism to disrupt the biofilm network is still not clearly understood. In this study, we performed in silico gene editing to exploit the AbaI gene, responsible for biofilm formation. The study explored different tools available for genome editing to create gene knockouts, selecting the A. baumannii AbaI gene as a target. Keywords: AbaI, Acinetobacter baumannii, CHOPCHOP, Crispr-cas9, sgRNA