Cytotoxic activity of methanolic extract of Streptomyces sp. strain KSF 83 on growth of human breast and colon cancer cells

Aims@#The attention for new and effective anticancer drugs but less toxic is increasing over time. Streptomyces is the most important and well-known source of their bioactive compound production with useful bioactivities. This work aimed for evaluation of the anticancer potential of methanolic extract of Streptomyces sp. strain KSF 83 against non-cancerous cell lines (CCD-841-CoN), breast (MCF-7, MDA-MB-231) and colon cancer cell lines (HT-29, HCT-116).@*Methodology and results@#The characteristic of the strain KSF 83 was identified by morphology and 16S rRNA sequencing and results confirmed that the strain belonged to the genus of Streptomyces. The crude substance was produced via submerged fermentation from the strain and methanol solvent was used to extract the culture filtrate. Methanolic extract possessed low toxicity against CCD-841-CoN with only 18% of inhibition activity at the 400 µg/mL. Among all tested cancer cells, the methanolic extract was able to inhibit the growth of all cancer cells tested with MCF-7 was the highest anticancer activity recorded. The methanolic extract also exhibited cytotoxicity in a range of EC50 of 65.79 μg/mL to 262.40 μg/mL. This study revealed the anticancer potential of Streptomyces sp. strain KSF 83, which could be sources of prospective anticancer drugs against breast and colon cancer.@*Conclusion, significance and impact of study@# The extract of KSF 83 was non-toxic toward normal cell lines and able to inhibit the growth of breast and cancer cell lines, thus it can be a potential source of the anticancer drug against breast and colon cancer.

Microbiological analysis of raw milk unveiled the presence of a dairy contaminant, Corynebacterium lipophiloflavum

Dairy farming occupied a distinct position in agriculture since milk can be harvested every day, providing a regularsource of income to the farmers. Development of the Malaysian dairy farming industry was marred by poor farmhygiene practices, leading to the proliferation of dairy-spoilage bacteria, affecting milk quality. In this study, wereport the isolation and characterization of a rare Corynebacterium species from raw milk after the implementationof improved farm hygiene practices. All milking equipment, farm worker’s hands and the cow’s udders and teatswere washed with detergent and wiped dry with clean towels before milk sample collection. Collected foremilksamples from mastitis-free cows were inoculated onto Petrifilm™ and cultured colonies were plated onto nutrientagar. Biochemical and molecular tests were performed for the identification of peculiar bacterial isolates. A uniqueyellow-pigmented bacteria isolate was recovered from the milk of a healthy cow after the adoption of improvedfarm hygiene practices. Phenotypic and genotypic characterization confirmed the milk isolate as Corynebacteriumlipophiloflavum. This is the first description of C. lipophiloflavum in cow’s milk and could possibly imply theinfluence of bovine flora in dairy contamination. The findings highlight the increasing spectrum of Corynebacteriumspecies with potential adverse impact to the dairy industry. It is recommended to screen for C. lipophiloflavum in allmilk processing facility to ensure that milk is safe for consumption and its products prepared to the highest qualityand safety standards.