PT  - JOURNAL ARTICLE
AU  - Mattiello-Franisco L.
AU  - Vieira F.M.
AU  - Peixoto G.
AU  - Mockaitis G.
TI  - Lactic Acid Production by <em>Clostridium acetobutylicum</em> and <em>Clostridium beijerinckii</em> Under Anaerobic Conditions Using a Complex Substrate
AID  - 10.1101/2021.02.23.432258
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.02.23.432258
4099  - http://biorxiv.org/content/early/2021/02/23/2021.02.23.432258.short
4100  - http://biorxiv.org/content/early/2021/02/23/2021.02.23.432258.full
AB  - High societies consumption, elevated residues generation and environmental awareness strengthen alternatives solutions for bioprocess’ residues. This study investigated the production of volatile acids from a complex substrate, which intends to be replaceable in the future by vinasse of sugar cane, in anaerobic reactors operated in triplicates at 35 °C. Two different inoculum were studied: Clostridium acetobutylicum ATCC 824 and Clostridium beijerinckii ATCC 25752. The nutrient medium had as carbon source a complex substrate containing sucrose without addition of vitamins, buffer solution and micronutrients. The experiment was conducted in the variation of F/M-ratio (food-to-microorganisms) by increasing substrate concentration.The concentration of sucrose in the complex substrate were 5.2 g·L-1 (conditions of 10,000 mg O2· L-1 in terms of COD) and 10.5 g· L-1 (conditions of 20,000 mg O2·L-1 in terms of COD), keeping the initial concentration of inoculum in 500 mg SVT·L-1. Cultures C. acetobutylicum and C. beijerinckii resulted in high lactic acid production. Concentrations of COD of 10,000 mg O2· L-1 produced optimum lactic acid of 3,331 mg·L-1 and 5,709 mg·L-1 with respectively C. acetobutylicum and C. beijerinckii. Moreover, cultures C. acetobutylicum and C. beijerinckii with 20,000 mg O2· L-1 concentrations in terms of COD produced optimum lactic acid of 6,417 mg· L-1 and 7.136 mg·L-1 respectively. There was repeatability in the reactors when considering level of significance of 0.05, independent of the concentration and inoculum used.Competing Interest StatementThe authors have declared no competing interest.