Response of acclimatized mesophilic biohydrogen cultures to feed changes

Abstract

This study investigated the response of acclimatized anaerobic hydrogen-producing cultures to substrate changes in batches. Two sequential batches were tested using non-acclimatized and acclimatized microbial cultures for biohydrogen production from different sugars. The first set of batches was conducted using non-acclimatized sludge with glucose at a concentration of 10g/L. The second set of batches was conducted using sludge acclimatized with glucose over a period of 4days from the first batch and a mixture of pentoses and hexoses (C5 & C6) sugars as the carbon sources. Additionally, two batches were tested: one with glucose, cellobiose, xylose, and arabinose individually with non acclimatized sludge, followed by C5 sugar batches. The acclimatized microbial cultures achieved a better performance compared to the non-acclimatized ones; the average hydrogen yield for glucose with non-acclimatized sludge was 1.71molH2/molglucose added (225mLH2/gCOD) compared to 1.9molH2/molglucose (250mLH2/gCOD), with glucose-acclimatized cultures. On the other hand, operating integrated biohydrogen reactor clarifier systems (IBRCSs) using equal amounts of glucose, cellobiose, arabinose, and xylose at a concentration of 2.5g/L each resulted in a hydrogen yield of 1.9molH2/molsugar added with a hydrogen production rate of 61.7LH2/d.