genus clostridium
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Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 264
Author(s):  
Luca Ricci ◽  
Valeria Agostino ◽  
Debora Fino ◽  
Angela Re

Gas fermentation by acetogens of the genus Clostridium is an attractive technology since it affords the production of biochemicals and biofuels from industrial waste gases while contributing to mitigate the carbon cycle alterations. The acetogenic model organisms C. ljungdahlii and C. autoethanogenum have already been used in large scale industrial fermentations. Among the natural products, ethanol production has already attained industrial scale. However, some acetogens are also natural producers of 2,3-butanediol (2,3-BDO), a platform chemical of relevant industrial interest. Here, we have developed a lab-scale screening campaign with the aim of enhancing 2,3-BDO production. Our study generated comparable data on growth and 2,3-BDO production of several batch gas fermentations using C. ljungdahlii and C. autoethanogenum grown on different gas substrates of primary applicative interest (CO2 · H2, CO · CO2, syngas) and on different media featuring different compositions as regards trace metals, mineral elements and vitamins. CO · CO2 fermentation was found to be preferable for the production of 2,3-BDO, and a fair comparison of the strains cultivated in comparable conditions revealed that C. ljungdahlii produced 3.43-fold higher titer of 2,3-BDO compared to C. autoethanogenum. Screening of different medium compositions revealed that mineral elements, Zinc and Iron exert a major positive influence on 2,3-BDO titer and productivity. Moreover, the CO2 influence on CO fermentation was explored by characterizing C. ljungdahlii response with respect to different gas ratios in the CO · CO2 gas mixtures. The screening strategies undertaken in this study led to the production of 2.03 ± 0.05 g/L of 2,3-BDO, which is unprecedented in serum bottle experiments.


2021 ◽  
Vol 14 (5) ◽  
pp. 49-55
Author(s):  
O. O. Tigunova ◽  

Aim. The purpose of the study was to investigate the effect of ultrasonic disintegration on the lignocellulosic raw materials (biomass of the non-cereal part of rape) with its subsequent use as a substrate for the production of biobutanol. Methods. Butanol-producing strains and the biomass of the non-cereal part of rape Brassica napus were used in the present study. Ultrasonic disintegration of lignocellulosic raw materials was performed on the specially designed equipment. Results. The effect of ultrasonic disintegration on lignocellulosic raw materials was investigated for further application in biofuel production based on microbiological conversion. The possibility of using the obtained components after the pre-treatment of lignocellulose by ultrasonic disintegration as a substrate for the microbiological synthesis of butanol was shown. The highest accumulation of butanol (2.4 g/l) was obtained with the use of 5% dry matter content in the medium, 5 min treatment and the specific power of ultrasonic disintegration of 0.72 W/ml. Conclusions. The possibility of producer strains of the genus Clostridium to use cellulose in the fermentation process has been shown. When using ultrasonic disintegration for pretreatment of the non-cereal part of the biomass of rape, the accumulation of butanol increased by 3 folds.


Author(s):  
Janaina Iltchenco ◽  
Vanessa Peruzzo ◽  
Flaviane Eva Magrini ◽  
Letícia Marconatto ◽  
Ana Paula Torres ◽  
...  

Abstract The vinasse is a residue of ethanol production with the potential for methane production, requiring an allochthonous inoculum. Several microorganisms act in the different phases of anaerobic digestion, and the identification of these microbial communities is essential to optimize the process. The characterization of the microbiota involved in the biodigestion of vinasse was observed in the initial stage (IS), at the peak of methane production (MS) and the end of the process (FS) of the best performance assay by high-throughput sequencing. The highest methane production was 0.78 mmolCH4.gVS.h−1 at 243.7 h in the substrate/inoculum ratio of 1.7, with consumption partial of acetic, propionic and isobutyric acids and an 82% reduction of COD. High microbial diversity was found. The genus Clostridium, Acinetobacter, Candidatus Cloacamonas, Bacteroides, Syntrophomonas, Kosmotoga, the family Porphyromonadaceae and the class Bacteroidia were the most abundant in the maximum methane production. Methane production was driven by Methanobacterium and Methanosaeta, suggesting the metabolic pathways using were hydrogenotrophic and acetoclastic.


2021 ◽  
pp. 125942
Author(s):  
Ju-Hyeong Jung ◽  
Young-Bo Sim ◽  
Jong-Hyun Baik ◽  
Jong-Hun Park ◽  
Saint Moon Kim ◽  
...  

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 898
Author(s):  
Hebatoallah Hassan ◽  
Daniel St-Gelais ◽  
Ahmed Gomaa ◽  
Ismail Fliss

Clostridium tyrobutyricum spores survive milk pasteurization and cause late blowing of cheeses and significant economic loss. The effectiveness of nisin-producing Lactococcus lactis ssp. lactis 32 as a protective strain for control the C. tyrobutyricum growth in Cheddar cheese slurry was compared to that of encapsulated nisin-A. The encapsulated nisin was more effective, with 1.0 log10 reductions of viable spores after one week at 30 °C and 4 °C. Spores were not detected for three weeks at 4 °C in cheese slurry made with 1.3% salt, or during week 2 with 2% salt. Gas production was observed after one week at 30 °C only in the control slurry made with 1.3% salt. In slurry made with the protective strain, the reduction in C. tyrobutyricum count was 0.6 log10 in the second week at 4 °C with both salt concentration. At 4 °C, nisin production started in week 2 and reached 97 µg/g after four weeks. Metabarcoding analysis targeting the sequencing of 16S rRNA revealed that the genus Lactococcus dominated for four weeks at 4 °C. In cheese slurry made with 2% salt, the relative abundance of the genus Clostridium decreased significantly in the presence of nisin or the protective strain. The results indicated that both strategies are able to control the growth of Clostridium development in Cheddar cheese slurries.


2020 ◽  
Vol 10 (12) ◽  
pp. 4063
Author(s):  
Beata Nalepa ◽  
Sławomir Ciesielski ◽  
Marek Aljewicz

The aim of this study was to evaluate the microbiome of industrially produced ripened Edam cheeses by next-generation sequencing. The samples for analyses were collected in spring and autumn. Spring samples were characterized by significantly higher Lactococcus and Bacillus counts and lower counts of Enterobacteriaceae, Enterococcus, and yeasts than autumn samples. The predominant microorganisms identified by the Illumina high-throughput sequencing technology belonged to four phyla: Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes. The dominant species were starter culture bacteria. Lactobacillus rhamnosus, Lactobacillus kefiri, Lactobacillus kefiranofaciens, Lactobacillus casei, Streptococcus thermophilus, and Bifidobacterium had the highest share of microbial cheese communities. The number of γ-Proteobacteria reads was higher in autumn cheese samples. A high number of reads was also noted in the genus Clostridium. The counts of spore-forming bacteria of the genus Bacillus were higher in cheeses produced in spring. The study revealed highly similar relationships between the analyzed production periods. The present results contribute to the existing knowledge of cheese microbiota, and they can be used to improve and modify production processes based on the composition of microbial communities, as well as to improve the quality of the final product.


Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 936 ◽  
Author(s):  
Xiao-Haitzi Daniel Puón-Peláez ◽  
Neil Ross McEwan ◽  
José Guadalupe Gómez-Soto ◽  
Roberto Carlos Álvarez-Martínez ◽  
Andrea Margarita Olvera-Ramírez

Epizootic rabbit enteropathy (ERE) affects young rabbits and represents 32% of the enteropathies in rabbit production farms in Mexico. The etiology of this syndrome has not been clarified yet. A metataxonomic and histopathology study of ERE was carried out to compare the gastrointestinal microbiota and histopathological lesions of healthy and positive-ERE rabbits. The metataxonomic study was done using an Illumina MiSeq (MiSeq® system, Illumina, San Diego California, USA) massive segmentation platform, and a Divisive Amplicon Denoising Algorithm 2 (DADA2 algorithm) was used to obtain Shannon and Simpson diversity indices as well as the relative abundance of the identified communities. For the histopathological study, paraffin sections of the cecum, ileo-cecal valve, and colon were stained with eosin and hematoxylin. AxioVision 4.9 software (Carl Zeiss MicroImaging GmbH, Jena, Germany) was used to measure the crypt depths. Statistical analysis was done using PERMANOVA analysis for the metataxonomic study and ANOVA for the histopathology study. Histopathologic analysis showed smaller sizes of crypts in the colon of ERE rabbits. Differences were observed in the diversity and abundance of the gastrointestinal microbiota between the analyzed groups. The genus Clostridium and the species Cloacibacillus porcorum and Akkermansia muciniphila were associated with ERE. The results obtained from this study can provide information for future clarification of the etiology and proposals of effective treatments.


Author(s):  
M. V. Kuznetsova ◽  
◽  
М. G. Маммаеvа ◽  
L. V. Кirichenko ◽  
M. A. Shishkin ◽  
...  

The diversity of microbial communities the artificial salt constructions (ASC) located in the medicalpreventive and sanatorium institutions of the Perm region was studied. It was found that the surfaces of the abiotic salt of all ASC were contaminated with microorganisms, and a significant difference was found between the constructions of sylvinite (86.5% of positive samples) and halite (47.4%). The number of viable bacteria, as well as staphylococci, were also higher in sylvinite constructions than in halite ones. Based on bacteriological research and analysis of the 16S rRNA gene nucleotide sequences, the isolated staphylococcus strains belong to the following species: Staphylococcus epidermidis – 42.3% (n=11), S. aureus and S. saprophyticus – 19.2% (n=5), S. simulans – 7.7% (n=2) and one strain of S. cohnii urealyticum, S. hominis, S. warneri – 3.8%. The species composition of microbiocenoses formed on surfaces determined by gas chromatography–mass spectrometry included representatives of 18 genera belonging to the three main phylums: Actinobacteria, Firmicutes and Proteobacteria. Actinobacteria (Actinomyces, Corynebacterium, Nocardia, Propionibacterium, Rhodococcus, etc.) were dominant in both groups ASC. Among Firmicutes, representatives of the genus Clostridium predominated in sylvinite ASC – 63.8% of the total number of bacteria, while in halite they were half as many – 32.1%. The content of coccal microbiota, in contrast, in halite constructions was almost 3 times higher than in sylvinite. Identified quantitative and qualitative indicators of the microbiota of the ASC complement the understanding of the constructions of microbial communities under conditions of high salt load and anthropogenic impact.


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