Bioactivities of Free and Encapsulated Streptomyces gougerotii NSH Extract Isolated from Itay Al Baroud, Egypt: Antifungal, Antitumor, and Water Bioremediation Potential in El-Mex Fish Farms

Discovering microbial capabilities in the environment has become significant to discover novel metabolites for biotechnological aspects.The present study was designated to study the diversity of actinomycetes in different soil samples (E1-E21) collected from Itay Al Baroud soil, El-Beherra, Egypt. The highest counts of actinomycetes were observed at the sampling site E15 with 267 CFU g^-1. Twenty-one selected isolatesnominated as N1-N21 were characterized based on physiological, biochemical tests and antimicrobial activity. The isolate N7 exhibited broad spectrum of antimicrobial potential against Staphylococcus aureus ATCC25923, Escherichia coli ATCC8739, Pseudomonas aeruginosa ATCC9027, Bacillus subtilis ATCC 6633, Enterococcus fecalis ATCC29212 and Klebsiella pneumoniae ATCC13883 with mean of inhibition zone diameters as 14-16mm. N7 was identified on the basis of the morphological, cultural, biochemical characteristics, 16S rRNA sequence analysis as Streptomyces gougerotii NSH MW023664. The extracted bioactive metabolites exhibited antifungal activity with mean of inhibition zone diameter at 8-22mm. The antitumor activity against MCF- 7, PC 3 and HCT-116 cell lines was tested. The highest inhibition rates (90.6% and 92.5%) were observed against PC-3 and HCT-116 cell lines at a concentration of 10,000µg/ mL, with IC₅₀ values of 3,460.45 and 4,113.75µg/ mL, respectively. The effectiveness of both free and encapsulated extracts in reducing fish pathogens in the rearing water of the El-Mex fish farm was investigated. The encapsulated extract showed greater efficacy, resulting in reductions of 90.2%, 83.3%, and 85.5% in Vibrio, Aeromonas, and Pseudomonas counts, respectively, compared to the free extract. These findings support the potential use of S. gougerotii NSH MW023664 as a probiotic in aquaculture.