Assembly of hyperhalophilic complex consortia of isolates from anchovy ripening attaining histamine degradation and their microbiome configuration

Abstract

High histamine content in salted-ripened fish results in food safety detriment. The present study focused on the assembly of mixed cultures from halophilic prokaryotes isolated during salting-ripening anchovy process in order to determine their histamine-degrading capacity. For this purpose, 57 halophilic prokaryotes were inoculated together and submitted to several enrichment steps with strong shifts in culturing conditions and three microbial consortia were subsequently assembled: original consortium named C1 (without histamine exposure), consortium C2 (enriched in nutritive culture medium with high histamine content ~900 mg/kg) and consortium C3 (against histamine ~200 mg/kg) and reduced amounts of nutrients. These consortia were submitted to histamine-degrading capacity studies and 16S rRNA gene amplicons analysis. In the absence of histamine (C1), Salinivibro costicola (16.83%), Haloarcula spp. (11.08%) and Halococcus spp. (8.73%) were the most abundant. C2 presented ability to degrade histamine and major OTUs belonged to the family Halobacteriaceae and the genus Halomonas. C3 degraded histamine and predominant OTUs were from the family Halomonadaceae and the genus Chomohalobacter. Therefore, members of the archaeal family Halobacteriaceae and bacterial genera Halomonas and Chomohalobacter would be associated to histamine degradation and their potential as single or mixed starter cultures for improving salted-ripened foodstuff safety is promising.