Fermentative biohydrogen production from a novel combination of vermicompost as inoculum and mild heat-pretreated fruit and vegetable waste

Abstract

Please cite this article as: Pascualone M.J., Gómez Costa M.B., Dalmasso P.R. Fermentative biohydrogen production from a novel combination of vermicompost as inoculum and mild heat-pretreated fruit and vegetable waste. Keywords: Biohydrogen Dark fermentation Fruit and vegetable waste Vermicompost Mild heat-pretreated substrateThis study reports for the first time on biohydrogen production by dark fermentation using a novel combination of mild heatpretreated fruit and vegetable waste (FVW) as raw material and vermicompost as an economical source of hydrogen-producing bacteria. A suspension rich in reducing sugars obtained from FVW was used at different initial concentrations (5 to 25 g reducing sugars/L) during the bioprocess conducted in batch reactors at mesophilic temperature of 35 °C. The use of a mild heat-pretreated substrate and the consequent elimination of the natural microbiota present in the FVW led to higher hydrogen production than the control. Clostridium species, hydrogen-producing bacteria via butyric acid fermentation pathway, were the dominant microorganisms in the bioprocess. Hydrogen production, volumetric hydrogen production rate, and pretreated substrate degradation efficiency (63.0 mL/g VS, 372.6 mL/L/d, and 50% BOD5, respectively) obtained in the experiments performed with the highest substrate concentration demonstrated that the developed bioprocess was promising simultaneously leading to high hydrogen contents in biogas and high substrate removal efficiencies.

Investigating Dark Fermentation as a Sustainable Organic Waste Management Technology for Producing Biohydrogen From Fruit and Vegetable Waste

“…The graph shows that inoculum pre-treatment had a positive effect on hydrogen production. This is consistent with other research ndings [26, [27][28][29][30], which found that chemical and physical pre-treatment of the inoculum enhances hydrogen production. Figure 3 also shows that the different inoculum pre-treatments clearly had a varied effect on hydrogen production.…”

“…Scholars [13,27] agree that inhibition of hydrogen consuming bacteria can be temporary, adding that spore forming hydrogen consuming bacteria can reactivate after a period of time, forming new stable microbial communities that are adapted to the environment. Researchers [29] ,mention that it is also possible for an inoculum pre-treatment to also suppress non-sporing hydrogen producing bacteria while some sporulating hydrogen consuming bacteria (methane producers) manage to survive the harsh pre-treatment conditions. For example, [23] states that suppression of non-spore forming HPB from the genus Enterobacter can occur while sporulating HCB like Clostridium aceticum and Clostridium thermoautotrophicum can withstand pre-treatment.…”

A Review on Bacterial Contribution to Lignocellulose Breakdown into Useful Bio-Products

“…Biohydrogen is a clean energy carrier that is a by-product of microorganisms acting on organic biomass [ 126 ]. Bacteria that produce biohydrogen are either photosynthetic, aerobic, or anaerobic [ 127 ]. Bacillus , Enterobacter , Clostridium , Lactobacillus , and Bfidobacterium have been used to produce biohydrogen successfully [ 128 ].…”

Unraveling optimum culture composition for hydrogen and 5-aminolevulinic acid production by Rhodobacter sphaeroides O.U.001

“…For example, the formation of 86 mM acetate was reported upon dark fermentation of sugar beet molasses by Caldicellulosiruptor saccharolyticus [15]. Likewise, 76-91 % of the metabolites was found to be acetate in the dark fermentation effluent of fruit and vegetable waste [16]. In sequential hydrogen production process where dark fermentation is followed by photofermantation, acetate formed during dark fermentation is further converted into hydrogen by PNS bacteria in photofermentation stage thereby increasing the efficiency of the overall process.…”