Screening of Candida glabrata Clinical Isolates for Pyruvic Acid Production Potentials

Abstract

The increasing demand for pyruvic acid as a versatile platform chemical in the food, pharmaceutical, agricultural, and cosmetic industries has stimulated interest in cost-effective microbial fermentation strategies. This study investigated the potential of Candida glabrata isolates from clinical samples for pyruvic acid production. Swab samples were collected from hospitals in Port Harcourt, Rivers State, Nigeria, and processed for yeast isolation. A total of ten yeast isolates (GC1–GC10) were obtained and subjected to biochemical tests, molecular identification, and phylogenetic analysis. All isolates were negative for germ tube and urease tests but positive for glucose fermentation, consistent with Candida glabrata. Molecular characterization confirmed high similarity of isolates GC1 (94.6%) and GC3 (96.2%) to C. glabrata. Screening under submerged fermentation conditions revealed significant variation in pyruvic acid yield, ranging from 2.1 g/L to 31.3 g/L. Isolate GC3 produced the highest concentration (31.3 g/L), followed closely by GC1 (29.7 g/L), while isolates GC2 (2.1 g/L) and GC10 (3.7 g/L) exhibited the lowest yields. The variability in production suggests strain-specific differences in metabolic efficiency and pyruvate accumulation. Compared with previously reported yields from conventional yeast fermentations, the concentrations achieved in this study demonstrate the industrial promise of clinical C. glabrata isolates as robust producers of pyruvic acid. It is concluded that the study establish a valuable link between clinical microbiology and industrial biotechnology, highlighting the potential of clinical yeast isolates as novel resources for sustainable organic acid production.