Isolation and screening of yeast for single cell protein production

Abstract

Single cell protein (SCP) has emerged as a promising alternative source of protein to meet the increasing global demand for food and feed supplements. Yeasts are among the most widely utilized microorganisms for SCP production due to their rapid growth rate, high protein content, ability to utilize diverse substrates, and Generally Recognized as Safe (GRAS) status. The present study focuses on the isolation and screening of yeast strains for efficient single cell protein production. Samples were collected from various natural sources such as fruits, fermented foods, and soil, followed by serial dilution and cultivation on selective yeast media. Distinct yeast colonies were isolated based on morphological characteristics and purified through repeated streaking techniques. Preliminary identification was carried out using microscopic observation and biochemical tests. The isolated strains were screened for biomass production, growth rate, substrate utilization efficiency, and protein content under controlled laboratory conditions. Quantitative estimation of protein was performed using standard analytical methods, and the most promising isolates were selected based on their superior biomass yield and protein accumulation. The results demonstrated considerable variation among the isolates, with certain strains exhibiting high growth performance and elevated protein content, indicating their potential for SCP production. Optimization of culture conditions further enhanced biomass productivity and nutritional quality. The study highlights the importance of exploring naturally occurring yeast populations as sustainable sources of microbial protein. The selected yeast isolates may serve as suitable candidates for large-scale SCP production using inexpensive substrates, contributing to food security, waste valorization, and environmentally friendly protein generation. These findings provide a foundation for further research on strain improvement and industrial application of yeast-based single cell protein production technologies.

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