Hydrogen fermentation from apple pomace by a newly isolated Clostridium beijerinckii strain, HU-1.

Abstract

Aomori prefecture, in which Hirosaki University is located, has a low average annual number of hours of sunshine (1541.9 h in 2011) and a large amount of agricultural residues such as apple pomace, pruned branches from apple trees, and rice straw that consist of various sugars. Therefore, we selected a fermentation process for biological H₂ production. Apple pomace is one of the major agricultural residues in Aomori, and it would be useful to develop an effective application for it. In this article, we report that the insoluble material from apple pomace stimulated H₂ production by a newly isolated Clostridium beijerinckii strain, HU-1. HU-1 produced H₂ with a production rate of 14.5 mmol of H₂/L/h in a fed-batch culture at 37°C, pH 6.0, and we determined that HU-1 was one of the highest H₂-producing strains in Clostridia. When HU-1 was cultivated in a culture containing the insoluble material from apple pomace, HU-1 produced H₂ at a rate approximately 1.2-fold greater than that observed without the addition of the insoluble material from apple pomace.