Lactate-mediated medium-chain fatty acid production from expired dairy and beverage waste  

作　　者：Bin Bian Wenxiang Zhang Najiaowa Yu Wei Yang Jiajie Xu Bruce E.Logan Pascal E.Saikaly 

机构地区：[1]Water Desalination and Reuse Center(WDRC),King Abdullah University of Science and Technology(KAUST),Thuwal 23955-6900,Kingdom of Saudi Arabia [2]Environmental Science and Engineering Program,Biological and Environmental Science and Engineering(BESE)Division,King Abdullah University of Science and Technology(KAUST),Thuwal 23955-6900,Kingdom of Saudi Arabia [3]Department of Civil and Environmental Engineering,The Pennsylvania State University,University Park,PA,16802,USA [4]Research Centre of Ecology&Environment for Coastal Area and Deep Sea,Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou,511458,China [5]School of Marine Science,Ningbo University,Ningbo,315211,China

出　　处：《Environmental Science and Ecotechnology》2024年第5期278-286,共9页环境科学与生态技术（英文）

基　　金：supported by a Competitive Research Grant(URF/1/4069-01-01);Research Translation Fund(REI/1/4576-01-01)from King Abdullah University of Science and Technology(KAUST),Saudi Arabia.

摘　　要：Fruits,vegetables,and dairy products are typically the primary sources of household food waste.Currently,anaerobic digestion is the most used bioprocess for the treatment of food waste with concomitant generation of biogas.However,to achieve a circular carbon economy,the organics in food waste should be converted to new chemicals with higher value than energy.Here we demonstrate the feasibility of medium-chain carboxylic acid(MCCA)production from expired dairy and beverage waste via a chain elongation platform mediated by lactate.In a two-stage fermentation process,the first stage with optimized operational conditions,including varying temperatures and organic loading rates,transformed expired dairy and beverage waste into lactate at a concentration higher than 900 mM C at 43℃.This lactate was then used to produce>500 mM C caproate and>300 mM C butyrate via microbial chain elongation.Predominantly,lactate-producing microbes such as Lactobacillus and Lacticaseibacillus were regulated by temperature and could be highly enriched under mesophilic conditions in the firststage reactor.In the second-stage chain elongation reactor,the dominating microbes were primarily from the genera Megasphaera and Caproiciproducens,shaped by varying feed and inoculum sources.Cooccurrence network analysis revealed positive correlations among species from the genera Caproiciproducens,Ruminococcus,and CAG-352,as well as Megasphaera,Bacteroides,and Solobacterium,indicating strong microbial interactions that enhance caproate production.These findings suggest that producing MCCAs from expired dairy and beverage waste via lactate-mediated chain elongation is a viable method for sustainable waste management and could serve as a chemical production platform in the context of building a circular bioeconomy.

关 键 词：Microbial chain elongation Medium chain carboxylic acids Food waste FERMENTATION 

分 类 号：X799.3[环境科学与工程—环境工程]