Persson Karl, Onyema Vanessa O, Nwafor Ijeoma Princess, Peri Kameshwara V R, Otti Chika, Nnaemeka Priscilla, Onyishi Chioma, Okoye Sylvia, Moneke Anene, Amadi Onyetugo, Warringer Jonas, Geijer Cecilia
Department of Life Sciences, Chalmers University of Technology, Gothenburg, Västra Götaland County, Sweden.
Department of Chemistry and Molecular Biology, Gothenburg University, Gothenburg, Västra Götaland County, Sweden.
Appl Environ Microbiol. 2025 Jan 31;91(1):e0161524. doi: 10.1128/aem.01615-24. Epub 2024 Dec 31.
Bioprospecting can uncover new yeast strains and species with interesting ecological characteristics and valuable biotechnological traits, such as the capacity to convert different carbon sources from industrial side and waste streams into bioproducts. In this study, we conducted untargeted yeast bioprospecting in tropical West Africa, collecting 1,996 isolates and determining their growth in 70 different environments. While the collection contains numerous isolates with the potential to assimilate several cost-effective and sustainable carbon and nitrogen sources, we focused on characterizing the 203 strains capable of growing on lactose, the main carbon source in the abundant side stream cheese whey from dairy industries. Through internal transcribed spacer sequencing of the lactose-assimilating strains, we identified 30 different yeast species from both the and phyla, of which several have not previously been shown to grow on lactose, and some are candidates for new species. Observed differences in growth and ratios of intra- and extracellular lactase activities suggest that the yeasts use a range of different strategies to metabolize lactose. Notably, several basidiomycetous yeasts, including , , and , accumulated lipids up to 40% of their cell dry weight, proving that they can convert lactose into a bioproduct of significant biotechnology interest.
This study paves the way to a better understanding of the natural yeast biodiversity in the largely under-sampled biodiversity hotspot area of tropical West Africa. Our discovery of several yeasts capable of efficiently converting lactose into lipids underscores the value of bioprospecting to identify yeast strains with significant biotechnological potential, which can aid the transition to a circular bioeconomy. Furthermore, the extensive strain collection gathered will facilitate future screening and the development of new cell factories.
生物勘探可以发现具有有趣生态特征和有价值生物技术特性的新酵母菌株和物种，例如将工业副产品和废物流中的不同碳源转化为生物产品的能力。在本研究中，我们在热带西非进行了非靶向酵母生物勘探，收集了1996个分离株，并测定了它们在70种不同环境中的生长情况。虽然该收集物包含许多有潜力同化几种具有成本效益和可持续性的碳源和氮源的分离株，但我们重点研究了能够在乳糖上生长的203株菌株的特性，乳糖是乳制品行业丰富的副产品奶酪乳清中的主要碳源。通过对乳糖同化菌株的内部转录间隔区测序，我们从子囊菌门和担子菌门中鉴定出30种不同的酵母物种，其中几种以前未被证明能在乳糖上生长，有些是新物种的候选者。观察到的生长差异以及细胞内和细胞外乳糖酶活性的比率表明，酵母使用一系列不同的策略来代谢乳糖。值得注意的是，几种担子菌酵母，包括[具体物种1]、[具体物种2]和[具体物种3]，积累的脂质高达其细胞干重的40%，证明它们可以将乳糖转化为具有重大生物技术意义的生物产品。
本研究为更好地了解热带西非这个在很大程度上未被充分采样的生物多样性热点地区的天然酵母生物多样性铺平了道路。我们发现几种能够有效地将乳糖转化为脂质的酵母，突出了生物勘探对于鉴定具有重大生物技术潜力的酵母菌株的价值，这有助于向循环生物经济的转型。此外，收集到的大量菌株将便于未来的筛选和新细胞工厂的开发。
