Comparative genomics of Clostridium species associated with vacuum-packed meat spoilage.

Bacterial species belonging to the genus Clostridium have been recognized as causative agents of blown pack spoilage (BPS) in vacuum packed meat products. Whole-genome sequencing of six New Zealand psychrotolerant clostridia isolates derived from three meat production animal types and their environments was performed to examine their roles in BPS. Comparative genome analyses have provided insight into the genomic diversity and physiology of these bacteria and divides clostridia into two separate species clusters. BPS-associated clostridia encode a large and diverse spectrum of degradative carbohydrate-active enzymes (CAZymes) that enable them to utilize the intramuscular carbohydrate stores and facilitate sporulation. In total, 516 glycoside hydrolases (GHs), 93 carbohydrate esterases (CEs), 21 polysaccharide lyases (PLs), 434 glycosyl transferases (GTs) and 211 carbohydrate-binding protein modules (CBM) with predicted activities involved in the breakdown and transport of carbohydrates were identified. Clostridia genomes have different patterns of CAZyme families and vary greatly in the number of genes within each CAZy category, suggesting some level of functional redundancy. These results suggest that BPS-associated clostridia occupy similar environmental niches but apply different carbohydrate metabolism strategies to be able to co-exist and cause meat spoilage.

Complete genome sequence of the rumen bacterium Butyrivibrio fibrisolvens D1T.

Butyrivibrio are anaerobic bacteria and members of the family Lachnospiraceae with important roles in fiber digestion in both animals and humans. This report describes the complete genome of Butyrivibrio fibrisolvens type strain D1T (DSM 3071) consisting of a chromosome (CP146963), megaplasmid (pNP243), and small plasmid (pNP21).

Complete genome sequence of Methanosphaera sp. ISO3-F5, a rumen methylotrophic methanogen.

Methanosphaera spp. are methylotrophic methanogenic archaea and members of the order Methanobacteriales with few cultured representatives. Methanosphaera sp. ISO3-F5 was isolated from sheep rumen contents in New Zealand. Here, we report its complete genome, consisting of a large chromosome and a megaplasmid (GenBank accession numbers CP118753 and CP118754, respectively).

Genome collection of Shewanella spp. isolated from spoiled lamb.

The diversity of the genus Shewanella and their roles across a variety of ecological niches is largely unknown highlighting the phylogenetic diversity of these bacteria. From a food safety perspective, Shewanella species have been recognized as causative spoilage agents of vacuum-packed meat products. However, the genetic basis and metabolic pathways for the spoilage mechanism are yet to be explored due to the unavailability of relevant Shewanella strains and genomic resources. In this study, whole-genome sequencing of 32 Shewanella strains isolated from vacuum-packaged refrigerated spoiled lamb was performed to examine their roles in meat spoilage. Phylogenomic reconstruction revealed their genomic diversity with 28 Shewanella spp. strains belonging to the same putative novel species, two Shewanella glacialipiscicola strains (SM77 and SM91), Shewanella xiamenensis NZRM825, and Shewanella putrefaciens DSM 50426 (ATCC 8072) isolated from butter. Genome-wide clustering of orthologous gene families revealed functional groupings within the major Shewanella cluster but also considerable plasticity across the different species. Pan-genome analysis revealed conserved occurrence of spoilage genes associated with sulfur and putrescine metabolism, while the complete set of trimethylamine metabolism genes was observed in only Shewanella sp. SM74, S. glacialipiscicola SM77 and SM91 strains. Through comparative genomics, some variations were also identified pertaining to genes associated with adaptation to environmental cues such as temperature, osmotic, salt, oxidative, antimicrobial peptide, and drug resistance stresses. Here we provide a reference collection of draft Shewanella genomes for subsequent species descriptions and future investigations into the molecular spoilage mechanisms for further applications in the meat industry.

Draft Genome Sequence of Clostridium bowmanii DSM 14206T, Isolated from an Antarctic Microbial Mat.

Clostridium bowmanii type strain DSM 14206 (ATCC BAA-581) was isolated from a microbial mat sample retrieved from Lake Fryxell, Antarctica. This report describes the generation and annotation of the 4.9-Mb draft genome sequence of C. bowmanii DSM 14206T.

Occurrence of genes encoding spore germination in Clostridium species that cause meat spoilage.

Members of the genus Clostridium are frequently associated with meat spoilage. The ability for low numbers of spores of certain Clostridium species to germinate in cold-stored vacuum-packed meat can result in blown pack spoilage. However, little is known about the germination process of these clostridia, despite this characteristic being important for their ability to cause spoilage. This study sought to determine the genomic conditions for germination of 37 representative Clostridium strains from seven species (C. estertheticum, C. tagluense, C. frigoris, C. gasigenes, C. putrefaciens, C. aligidicarnis and C. frigdicarnis) by comparison with previously characterized germination genes from C. perfringens, C. sporogenes and C. botulinum. All the genomes analysed contained at least one gerX operon. Seven different gerX operon configuration types were identified across genomes from C. estertheticum, C. tagluense and C. gasigenes. Differences arose between the C. gasigenes genomes and those belonging to C. tagluense/C. estertheticum in the number and type of genes coding for cortex lytic enzymes, suggesting the germination pathway of C. gasigenes is different. However, the core components of the germination pathway were conserved in all the Clostridium genomes analysed, suggesting that these species undergo the same major steps as Bacillus subtilis for germination to occur.

Draft Genome Sequence of Clostridium sp. Strain FP1, with Similarity to Clostridium tagluense, Isolated from Spoiled Lamb.

Clostridium sp. strain FP1 was isolated from vacuum-packaged refrigerated spoiled lamb, and this article describes its 5.4-Mb draft genome sequence. The FP1 genome was sequenced to facilitate source tracking and attribution studies, adding to our understanding of the role of Clostridium species in premature spoilage of red meats.

Whole-Genome Sequencing of Clostridium sp. Strain FP2, Isolated from Spoiled Venison.

Clostridium sp. strain FP2 was isolated from vacuum-packaged refrigerated spoiled venison in New Zealand. This report describes the generation and annotation of the 5.6-Mb draft genome sequence of Clostridium sp. FP2, which will facilitate future functional genomic studies to improve our understanding of premature spoilage of red meats.

Draft Genome Sequence of Psychrotolerant Clostridium sp. Strain M14, Isolated from Spoiled Uncooked Venison.

Clostridium sp. strain M14 was isolated from vacuum-packaged refrigerated spoiled venison, and this report describes the generation and annotation of its 3.9-Mb draft genome sequence.

Draft Genome Sequence of Clostridium estertheticum-like Strain FP4, Isolated from Spoiled Uncooked Lamb.

In order to improve the phylogenetic resolution of the genus Clostridium and our limited knowledge of meat spoilage caused by Clostridium estertheticum, the genome of C. estertheticum-like strain FP4 was sequenced. Here, we describe the 4.1-Mb draft genome sequence of C. estertheticum-like strain FP4, isolated from vacuum-packaged refrigerated spoiled lamb.

Draft Genome Sequence of Clostridium estertheticum-Like Strain FP3, Isolated from Spoiled Uncooked Lamb.

Clostridium estertheticum-like strain FP3 was isolated from vacuum-packaged refrigerated spoiled lamb. This bacterium is psychrotrophic, Gram positive, spore-forming, and a strict anaerobe. Here, we report the generation and annotation of the 5.6-Mb draft genome sequence of C. estertheticum-like strain FP3.

Draft Genome Sequence of Clostridium estertheticum subsp. laramiense DSM 14864T, Isolated from Spoiled Uncooked Beef.

Clostridium estertheticum subsp. laramiense type strain DSM 14864 (ATCC 51254) was isolated from vacuum-packaged refrigerated spoiled beef. This report describes the generation and annotation of the 5.0-Mb draft genome sequence of C. estertheticum subsp. laramiense DSM 14864T.