Helicovermis profundi gen. nov., sp. nov., a novel mesophilic, asporogenous bacterium within the Clostridia isolated from a deep-sea hydrothermal vent chimney.

A novel mesophilic bacterial strain, designated S502T, was isolated from a deep-sea hydrothermal vent at Suiyo Seamount, Japan. Cells were Gram-positive, asporogenous, motile, and curved rods, measuring 1.6-5.6 µm in length. The strain was an obligate anaerobe that grew fermentatively on complex substrates such as yeast extract and Bacto peptone. Elemental sulfur stimulated the growth of the strain, and was reduced to hydrogen sulfide. The strain grew within a temperature range of 10-23 °C (optimum at 20 °C), pH range of 4.8-8.3 (optimum at 7.4), and a NaCl concentration range of 1.0-4.0% (w/v) (optimum at 3.0%, w/v). Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the isolate was a member of the class Clostridia, with Fusibacter paucivorans strain SEBR 4211T (91.1% sequence identity) being its closest relative. The total size of the genome of the strain was 3.12 Mbp, and a G + C content was 28.2 mol%. The highest values for average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) value of strain S502T with relatives were 67.5% (with Marinisporobacter balticus strain 59.4MT), 51.5% (with M. balticus strain 59.4MT), and 40.9% (with Alkaliphilus serpentinus strain LacTT), respectively. Based on a combination of phylogenetic, genomic, and phenotypic characteristics, we propose strain S502T to represent a novel genus and species, Helicovermis profundi gen. nov., sp. nov., with the type strain S502T (= DSM 112048T = JCM 39167T).

Research progress on ecological adaptation and prevention of Parengyodontium album on the surface of cultural relics.

Cultural relics as the crystallization of human history are non-renewable and irreplaceable resources. Microorganisms are widely colonized on ancient wall paintings, stone cultural relics, and other types of cultural heritages to cause harm. The dominant disease fungus, Parengyodontium album, is extensively distributed and can seriously threaten the long-term preservation of precious cultural heritage due to surviving in various cultural relics and extreme environments. The classification and nomenclature of P. album have undergone several changes, so its impact on cultural relic received little attention. Here, we summarized the brief histories of its classification and development, distribution range, and cultural heritage preference of P. album. We further analyzed the physiological, biochemical, and ecological characteristics and potential biological degradation mechanism. We proposed that P. album could be used as an indicative species of microbial hazardous effects on cultural heritage. We discussed the prevention and control countermeasures of such typical mural microorganisms and pointed out key research directions in this field.

Geochip 5.0 insights into the association between bioleaching of heavy metals from contaminated sediment and functional genes expressed in consortiums.

The heavy metal contamination in river and lake sediments endangers aquatic ecosystems. Herein, the feasibility of applying different exogenous mesophile consortiums in bioleaching multiple heavy metal-contaminated sediments from Xiangjiang River was investigated, and a comprehensive functional gene array (GeoChip 5.0) was used to analyze the functional gene expression to reveal the intrinsic association between metal solubilization efficiency and consortium structure. Among four consortiums, the Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans consortium had the highest solubilization efficiencies of Cu, Pb, Zn, and Cd after 15 days, reaching 50.33, 29.93, 47.49, and 79.65%, while Cu, Pb, and Hg had the highest solubilization efficiencies after 30 days, reaching 63.67, 45.33, and 52.07%. Geochip analysis revealed that 31,346 genes involved in different biogeochemical processes had been detected, and the systems of 15 days had lower proportions of unique genes than those of 30 days. Samples from the same stage had more genes overlapping with each other than those from different stages. Plentiful metal-resistant and organic remediation genes were also detected, which means the metal detoxification and organic pollutant degradation had happened with the bioleaching process. The Mantel test revealed that Pb, Zn, As, Cd, and Hg solubilized from sediment influenced the structure of expressed microbial functional genes during bioleaching. This work employed GeoChip to demonstrate the intrinsic association between functional gene expression of mesophile consortiums and the bioleaching efficiency of heavy metal-contaminated sediment, and it provides a good reference for future microbial consortium design and remediation of river and lake sediments.

Microbial contamination in industrial tofu / Contaminação microbiana em tofu industrial

ABSTRACT: This study aimed to evaluate the microbiological quality of tofu sold in supermarkets in Porto Alegre/Brazil. Bacteria counts were performed for Bacillus cereus , mesophilic, coliforms and Staphylococcus coagulase positive and negative. The presence of Listeria sp. was also evaluated. Two different brands of tofu (A and B) were collected, one lot per month, for six months. Five samples from each lot were analyzed. All lots presented mesophilic aerobic counts above 4.3x105CFU g-1. Four of the six lots from brand A and all lots from brand B showed E. coli and/or Staphylococcus coagulase positive counts above the Brazilian law accepted limits. The Staphylococcus coagulase negative counts were higher than those of coagulase positive in all lots. In all lots where Staphylococcus coagulase positive counts were above the legal limit, there were counts of coagulase negative above 104CFU g-1. B. cereus and Listeria sp. were not found in either brand. The majority of lots of brand A and all lots of brand B were unsuitable for human consumption. Our results showed that there are problems in tofu manufacturing in both industries analyzed. There is a need of improvement on its microbial quality to avoid problems of food-borne illness, and finally the need of a better control by the Brazilian inspection services.

RESUMO: Este estudo teve como objetivo avaliar a qualidade microbiológica de queijo tofu comercializados em um supermercado da cidade de Porto Alegre, RS. Foram realizadas contagens de Bacillus cereus , bactérias mesófilas, coliformes, Staphylococcus coagulase positive e negativo e, a pesquisa de Listeria sp. Foi realizada a coleta de duas diferentes marcas (A e B), com um lote por mês, durante seis meses; sendo analisadas cinco amostras de cada lote. Todos os lotes apresentaram contagens de mesófilos aeróbios acima de 4,3x105UFC g-1. Quatro dos seis lotes da marca A e todos os lotes da marca B apresentaram contagens de E. coli e/ou Staphylococcus coagulase positive acima do permitido pela legislação vigente. As contagens de Staphylococcus coagulase negativos foram superiores às contagens dos coagulase positivos em todos os lotes. Nos lotes em que foram encontradas contagens fora do padrão estabelecido para os Staphylococcus coagulase positivos, havia contagens dos coagulase negativos acima de 104UFC g-1. Não foram isolados B. cereus e Listeria sp. Ambas as marcas apresentaram sérios problemas sanitários, pois a maioria dos lotes da marca A e todos os lotes da marca B estavam impróprios para o consumo mesmo na ausência dos outros patógenos pesquisados. Nossos resultados mostram que há problemas sérios na produção de tofu em ambas as indústrias analisadas. Existe a necessidade de melhorias no sistema de produção para evitar a ocorrência de doenças causadas por este alimento e, também, que deve haver um maior controle da qualidade deste alimento pelos serviços de fiscalização.

Análise da qualidade sanitária de vegetais minimamente processados em embalagens com e sem atmosfera modificada / Analysis of the sanitary quality of minimally processed vegetables in packaging with and without modified atmosphere

O consumo de alimentos minimamente processados tem aumentado nos últimos anos devido a sua praticidade e conveniência. O presente trabalho teve como objetivo analisar a qualidade microbiológica e parasitológica de vegetais minimamente processados armazenados em diferentes tipos de embalagens. Foram adquiridas 70 amostras aleatoriamente nos hipermercados no município de Taubaté, SP; sendo 30 embaladas em atmosfera modificada, e 40 em embalagens sem atmosfera modificada. Foram realizadas análises de coliformes totais e coliformes termotolerantes; Escherichia coli; bactérias aeróbias mesófilas e detecção de Salmonella. As amostras com e sem atmosfera modificada apresentaram coliformes totais maior que 103 NMP/g em 9 (63,3%) e 28 (70%), respectivamente. Em ambos os grupos a contagem de bactérias aeróbias mesófilas estavam acima de 106 UFC/g; coliformes termotolerantes menor que 102 NMP/g e ausência de Salmonella. Não houve diferença na contagem de coliformes totais e bactérias aeróbias mesófilas nos dois tipos de embalagens. As amostras analisadas neste trabalho apresentaram altas contagens de bactérias aeróbias mesófilas e coliformes totais, estes resultados podem contribuir para alertar as autoridades sanitárias para o risco potencial destes produtos para o consumidor.

The consumption of minimally processed foods has increased in recent years due to its practicality and convenience. This study aimed to examine the microbiological quality of minimally processed vegetables stored in different types of packaging. They were purchased randomly 70 samples hypermarkets in Taubaté, SP, from March to November 2007, 30 packed in modified atmosphere, and 40 withoutmodified atmosphere packaging. Samples were evaluated for total coliforms and thermotolerants coliforms, Escherichia coli; aerobic mesophiles bacteria and Salmonella. The samples with and withoutmodified atmosphere had total coliforms greater than 103 NMP/g in 19 (63.3%) and 28 (70%), respectively. 1n both groups the count of aerobic mesophile bacteria were above of 105 CFU/g; thermotolerants coliforms less than 102 NMP/g and absence of Salmonella. Samples analyzed in this study showed high counts of aerobic mesophiles bacteria and total coliforms, these results may help to alert health authorities to the potential risk of these products to the consumer.