This study was carried out in the Food Science Department, Agriculture College, Basrah University to investigate the effect of different chitosan concentrations on drinking water quality. The studied parameters were turbidity, TDS, electrical conductivity and pH. The results showed that the turbidity, TDS, electrical conductivity and pH have been decreased with the increase of chitosan concentration. When chitosan concentration increased from 0 to 1g 100ml−1, the turbidity, TDS, electrical conductivity and pH were decreased from 1.98 to 0.98 NTU, 5.67 to 4.13gL−1, 10.18 to 5.27mScm−1, 6.1 to 5.71 respectively. The linear equations have represented the relationship between all parameters and chitosan concentration. However, the total bacteria count, total coliform bacteria, Staphylococci, Fecal coliform bacteria and Vibrio spp. have been eliminated completely by using Chitosan concentration of 0.8, 0.4, 0.8, 0.2 and 0.2g100ml−1 respectively

Aroma and flavour represent the key components of food that improves the organoleptic characteristics of food and enhances the acceptability of food to consumers. Commercial manufacturing of aromatic and flavouring compounds is from the industry's microbial source, but since time immemorial, its concept has been behind human practices. The interest in microbial flavour compounds has developed in the past several decades because of its sustainable way to supply natural additives for the food processing sector. There are also numerous health benefits from microbial bioprocess products, ranging from antibiotics to fermented functional foods. This review discusses recent developments and advancements in many microbial aromatic and flavouring compounds, their biosynthesis and production by diverse types of microorganisms, their use in the food industry, and a brief overview of their health benefits for customers.

A variety of organisms produce bioactive peptides that express inhibition activity against other organisms. Saccharomyces cerevisiae is considered the best example of a unicellular organism that is useful for studying peptide production. In this study, an antibacterial peptide was produced and isolated from Saccharomyces cerevisiae (Baker’s yeast) by an ultrafiltration process (two membranes with cut-offs of 2 and 10 kDa) and purified using the ÄKTA Pure 25 system. Antibacterial peptide activity was characterized and examined against four bacterial strains including Gram-positive and Gram-negative bacteria. The optimum condition for yeast growth and antibacterial peptide production against both Escherichia. coli and Klebsiella aerogenes was 25–30 °C within a 48 h period. The isolated peptide had a molecular weight of 9770 Da, was thermostable at 50–90 °C for 30 min, and tolerated a pH range of 5–7 at 4 °C and 25 °C during the first 24 h, making this isolated antibacterial peptides suitable for use in sterilization and thermal processes, which are very important aspect in food production. The isolated antibacterial peptide caused a rapid and steady decline in the number of viable cells from 2 to 2.3 log units of gram-negative strains and from 1.5 to 1.8 log units of gram-positive strains during 24 h of incubation. The isolated antibacterial peptide from Saccharomyces cerevisiae may present a potential biopreservative compound in the food industry exhibiting inhibition activity against gram-negative and gram-positive bacteria.