Gluconate metabolism and gas production by Paucilactobacillus wasatchensis WDC04

Paucilactobacillus wasatchensis, a nonstarter lactic acid bacteria, can cause late gas production and splits cracks in aging cheese when it metabolizes 6-carbon substrates, particularly galactose, to 5-carbon sugar, resulting the release of CO2. Previous studies have not explained no galactose is present. Based on genome sequence Pa. wasatchensis WDC04, genes for potential metabolic pathways were mapped using knowledgebase predictive biology software. This modeling predicted WDC04 could metabolize gluconate. Gluconate contains 6 carbons, convert 6-P-gluconate then ribulose-5-P by 6-phosphogluconate dehydrogenase decarboxylating step, producing CO2 during its metabolism. The goal this study was determine if sodium gluconate, often added reduce calcium lactate crystal formation, be metabolized production. Carbohydrate-restricted DeMan, Rogosa, Sharpe broth mixed with varying ratios ribose, or d-galactose (total substrate content 1% wt/vol). Oxyrase (Oxyrase Inc.; 1.8% vol/vol) also used mimic anaerobic environment selected tubes. Tubes inoculated 4-d culture WDCO4, results recorded over 8 d. When into carbohydrate-restricted containing only gluconate as substrate, grew, confirming utilization. Of 10 used, produced scenarios, most from ratio 100% ribose galactose. It confirmed that obligately heterofermentative lactobacilli such utilize produce gas. Addition thus becomes another risk factor unwanted formation slits cracks.