Pectinatus spp. - Unpleasant and recurrent brewing spoilage bacteria

Traditionally, beer has been recognised as a beverage with high microbiological stability because of the hostile growth environment posed by beer and increasing attention being paid to brewery hygiene. However, the microbiological risk has increased in recent years because of technological advances toward reducing oxygen in beers, besides the increase in novel beer styles production, such as non-pasteurised, flash pasteurised, cold sterilised, mid-strength, and alcoholic-free beer, that are more prone to spoilage bacteria. Moreover, using innovative beer ingredients like fruits and vegetables is an added cause of microbial spoilage. To maintain quality and good brand image, beer spoilage microorganisms are a critical concern for breweries worldwide. Pectinatus and Megasphaera are Gram-negative bacteria mostly found in improper brewing environments, leading to consumer complaints and financial losses. Because of the lack of compiled scientific knowledge on Pectinatus spoilage ability, this review provides a comprehensive overview of the occurrence, survival mechanisms, and the factors affecting beer spoilage Pectinatus species in the brewing process.

Opinions 97, 98 and 99

The International Committee on Systematics of Prokaryotes has formally endorsed the conclusions of the Judicial Commission on three pending Requests for an Opinion, thereby allowing the corresponding Opinions to be issued. According to Opinion 97, the request for the conservation of the name Streptomyces scabies is denied, allowing the continued use of the correction Streptomyces scabiei . Opinions 98 and 99 conclude that in the absence of associated authentic type material, the names Bacillus aeolius and Pectinatus portalensis , respectively, are not validly published.

What does Rule 18c of the International Code of Nomenclature of Bacteria really say?

A number of recent Requests for an Opinion have cited Rule 18c of the International Code of Nomenclature of Bacteria as the Rule governing setting a time limit on the search for a neotype strain. This Rule only governs what happens when a neotype is proposed and not what happens when the original type appears to have been lost and a neotype is not found. It is appropriate to emphasize this issue and to examine what other alternatives are available.

Pectinatus sottacetonis sp. nov., isolated from a commercial pickle spoilage tank

A strictly anaerobic, Gram-stain-negative, non-spore-forming, motile bacterium, designated strain FSRU B0405T, was isolated from a commercial pickle spoilage tank and characterized by biochemical, physiological and molecular biological methods. Analyses of the 16S rRNA gene sequence of strain FSRU B0405T showed affiliation to the class Negativicutes in the phylum Firmicutes , with the closest relatives being the type strains of Pectinatus haikarae (96 %) and Pectinatus brassicae (95 %). In maximum-likelihood and neighbour-joining phylogenetic trees, strain FSRU B0405T clustered definitively (in 100 % of bootstrapped trees) within the genus Pectinatus , but not specifically with any characterized species within this genus. Strain FSRU B0405T was a slightly curved rod, varying from 3 to 30 µm in length, motile with a distinctive X-wise movement, having flagella only on the concave side of the cell. The isolate produced acetate and propionate from fructose and glucose as major metabolites similar to type strains of species of the genus Pectinatus . The major fatty acids were C11 : 0, C13 : 0, C15 : 0, C13 : 0 3-OH, C17 : 1 and C18 : 1ω11t. Strain FSRU B0405T differed from the pickle wastewater strain, Pectinatus brassicae TYT, due to its lack of susceptibility to vancomycin, acetoin production, growth temperature range, acid production from adonitol, erythritol, glycerol, inositol, lactose, maltose, mannose, ribose, salicin, sorbitol, trehalose and xylitol and lack of hydrolysis of milk. Strain FSRU B0405T could be differentiated from other species of the genus Pectinatus both phenotypically and genetically. The results indicate that strain FSRU B0405T represents a novel species of the genus Pectinatus , for which the name Pectinatus sottacetonis sp. nov. is proposed. The type strain is FSRU B0405T ( = ATCC BAA-2501T = VTT E-113163T). An emended description of the genus Pectinatus is also provided.

Pectinatus brassicae sp. nov., a Gram-negative, anaerobic bacterium isolated from salty wastewater

A novel Gram-negative, non-spore-forming, strictly anaerobic, heterotrophic bacterium, strain TYT, was isolated from salty pickle wastewater. Cells were rod-shaped with comb-like flagella, slightly curved and very variable in length. Optimal growth occurred at 28 °C and pH 6.5. Cells were resistant to up to 50 g NaCl l−1. Strain TYT produced acid from glycerol, sucrose, glucose, fructose and mannitol. The main fermentation products from glucose were acetic and propionic acids. Tests for acid phosphatase and naphthol-AS-BI-phosphohydrolase activities were positive. The major fatty acids were C14 : 0 DMA (18.7 %), C15 : 0 (15.4 %), anteiso-C18 : 1 (15.2 %), C11 : 0 (13.3 %) and summed feature 5 (C17 : 1ω7c and/or C17 : 2) (11.0 %). The DNA G+C content was 35.9 mol%. 16S rRNA gene sequence-based phylogenetic analysis indicated that strain TYT represented a novel species of the genus Pectinatus (sequence similarity to other members of the genus ranged from 93.2 to 94.8 %). Based on its phenotypic, genotypic and phylogenetic characteristics, strain TYT is proposed to represent a novel species, named Pectinatus brassicae sp. nov. (type strain TYT  = JCM 17499T  = DSM 24661T).