Clostridium butyricum inhibits the inflammation in children with primary nephrotic syndrome by regulating Th17/Tregs balance via gut-kidney axis.

BACKGROUND: Primary nephrotic syndrome (PNS) is a common glomerular disease in children. Clostridium butyricum (C. butyricum), a probiotic producing butyric acid, exerts effective in regulating inflammation. This study was designed to elucidate the effect of C. butyricum on PNS inflammation through the gut-kidney axis. METHOD: BALB/c mice were randomly divided into 4 groups: normal control group (CON), C. butyricum control group (CON+C. butyricum), PNS model group (PNS), and PNS with C. butyricum group (PNS+C. butyricum). The PNS model was established by a single injection of doxorubicin hydrochloride (DOX) through the tail vein. After 1 week of modeling, the mice were treated with C. butyricum for 6 weeks. At the end of the experiment, the mice were euthanized and associated indications were investigated. RESULTS: Since the successful modeling of the PNS, the 24 h urine protein, blood urea nitrogen (BUN), serum creatinine (SCr), urine urea nitrogen (UUN), urine creatinine (UCr), lipopolysaccharides (LPS), pro-inflammatory interleukin (IL)-6, IL-17A were increased, the kidney pathological damage was aggravated, while a reduction of body weights of the mice and the anti-inflammatory IL-10 significantly reduced. However, these abnormalities could be dramatically reversed by C. butyricum treatment. The crucial Th17/Tregs axis in PNS inflammation also was proved to be effectively regulated by C. butyricum treatment. This probiotic intervention notably affected the expression levels of signal transducer and activator of transcription 3 (STAT3), Heme oxygenase-1 (HO-1) protein, and retinoic acid-related orphan receptor gamma t (RORγt). 16S rRNA sequencing showed that C. butyricum could regulate the composition of the intestinal microbial community and found Proteobacteria was more abundant in urine microorganisms in mice with PNS. Short-chain fatty acids (SCFAs) were measured and showed that C. butyricum treatment increased the contents of acetic acid, propionic acid, butyric acid in feces, acetic acid, and valeric acid in urine. Correlation analysis showed that there was a closely complicated correlation among inflammatory indicators, metabolic indicators, microbiota, and associated metabolic SCFAs in the gut-kidney axis. CONCLUSION: C. butyricum regulates Th17/Tregs balance via the gut-kidney axis to suppress the immune inflammatory response in mice with PNS, which may potentially contribute to a safe and inexpensive therapeutic agent for PNS.

Characteristics of an In Vitro Mesenteric Lymph Node Cell Suspension Model and Its Possible Association with In Vivo Functional Evaluation.

In a previous study, we uncovered three immune-responsive patterns of gut microbes using an in vitro mesenteric lymph node cell suspension model, abbreviated as the MLN model hereafter. We used Akkermansia muciniphila and Clostridium butyricum as the first group directly inducing an immune response, Bifidobacterium sp. and Bacteroides sp. as the second group evoking an immune response with the help of stimuli (anti-CD3 and anti-CD28 antibodies), and Lactobacillus sp. as the third group blunting the immune response with or without stimuli. Our group previously clarified the immune-activation characteristics of A. muciniphila and linked its in vivo immune induction effect in GF and SPF mice under homeostasis. In the present study, we supplemented the characteristics of C. butyricum and B. bifidum in the in vitro MLN model and addressed the specific elements of the model. Finally, we used an in vivo TNBS-challenge model to show the functional differences between these species with different response patterns in vitro. The results showed that C. butyricum and B. bifidum evoked an immune response in vitro in a dose-dependent and strain-unique manner. Although TLR2, rather than TLR4, is indispensable for immune activation in the present in vitro model, it may not involve interaction between TLR2 and bacterial ligands. Like the PBMC model, the present in vitro MLN model is highly dependent on cell resources and should be given more attention when used to conduct a quantitative comparison. Finally, a mixture of two strong immunogenic strains, A. muciniphila and C. butyricum, significantly increased the mortality of TNBS-challenged (2,4,6-trinitrobenzene sulfonic acid, TNBS) mice, indicating a possible link between the in vitro MLN model and in vivo functional evaluation. However, more evidence is needed to clarify the associations and underlying mechanisms.

Dietary Clostridium butyricum supplementation modifies significantly the liver transcriptomic profile in weaned piglets.

The addition of probiotics in swine nutrition is known to positively influence both health and growth. The current study investigates differences in the hepatic transcriptome profiles between weaned piglets supplemented with Clostridium butyricum (C. butyricum) and control animals that received no probiotic. The liver is an important metabolic organ that plays a critical role in oxidizing triglycerides for energy production, lipid synthesis and degradation, as well as immune regulation in animals. RNA-Seq analysis was carried out on total RNA harvested from the liver of piglets fed with (n = 3) or without (n = 3) 5 × 105 C. butyricum CFU/g. Compared to the control piglets, 588 of the genes examined (352 up-regulated and 236 down-regulated) were significantly differentially expressed at a fold change > 2 and p < .05 in animals fed with C. butyricum. Quantitative real-time reverse transcription PCR (qRT-PCR) analysis was further used to validate the microarray expression results for 28 genes tested. The functional annotation analyses revealed several genes, processes and pathways with putative involvement in piglet growth and performance. Feeding swine with 5 × 105 C. butyricum CFU/g appears to reinforce their immune status as well as foster the cell cycle and improve the metabolism of carbohydrates, lipids and amino acids. This study provides valuable information about the expression profiles of mRNAs in piglet liver and in-depth functional investigations of these mRNAs that could provide new insights into the molecular networks of growth, immune responses and nutrient metabolism in the porcine liver.

RNA-Seq transcriptome analysis of breast muscle in Pekin ducks supplemented with the dietary probiotic Clostridium butyricum.

BACKGROUND: Increased attention is being paid to breast muscle yield and meat quality in the duck breeding industry. Our previous report has demonstrated that dietary Clostridium butyricum (C. butyricum) can improve meat quality of Pekin ducks. However, the potential biological processes and molecular mechanisms that are modulated by dietary C. butyricum in the breast muscle of Pekin ducks remain unknown. RESULTS: Supplementation with C. butyricum increased growth performance and meat yield. Therefore, we utilized de novo assembly methods to analyze the RNA-Seq transcriptome profiles in breast muscle to explore the differentially expressed genes between C. butyricum-treated and control Pekin ducks. A total of 1119 differentially expressed candidate genes were found of which 403 genes were significantly up-regulated and 716 genes were significantly down-regulated significantly. qRT-PCR analysis was used to confirm the accuracy of the of RNA-Seq results. GO annotations revealed potential genes, processes and pathways that may participate in meat quality and muscle development. KEGG pathway analysis showed that the differentially expressed genes participated in numerous pathways related to muscle development, including ECM-receptor interaction, the MAPK signaling pathway and the TNF signaling pathway. CONCLUSIONS: This study suggests that long-time dietary supplementation with C. butyricum can modulate muscle development and meat quality via altering the expression patterns of genes involved in crucial metabolic pathways. The findings presented here provide unique insights into the molecular mechanisms of muscle development in Pekin ducks in response to dietary C. butyricum.

Broad Prebiotic Potential of Non-starch Polysaccharides from Oats (Avena sativa L.): an in vitro Study.

Prebiotics inducing the growth or activity of beneficial intestinal bacteria - probiotics producing short-chain fatty acids (SCFA) have lately received wide recognition for their beneficial influence on host intestinal microbiota and metabolic health. Some non-starch polysaccharides (NSP) are defined as prebiotics and oats being one of richest sources of NSP in grains are considered as potentially having prebiotic effect. However, information on fermentation of specific NSP of oats is limited. Moreover, bacterial cross-feeding interactions in which fermentation of prebiotics is involved is poorly characterized. Here, we report the exploration of new candidates for the syntrophic bacterial interactions and fermentability of oat non-starch polysaccharides (NSP). The results obtained by differentiating composition, viscosity and concentration of oats NSP in fermentation medium showed that Bacillus licheniformis pre-digests oat NSP, degrades high viscosity of oat ß-glucan and makes hemicellulose easier to access for other bacteria. Because of fermentation, B. licheniformis produces lactic and succinic acids, which further can be used by other bacteria for cross-feeding and SCFA production.

Clostridium butyricum partially regulates the development of colitis-associated cancer through miR-200c.

Colitis-associated cancer (CAC), one form of colorectal cancer (CRC),is an increasing concern worldwide. Both diagnosis and current therapy are challenging and bottlenecked. The aim of this study is to investigate novel mechanisms by which the therapeutic C. butyricum regulates colitis-induced oncogenesis. Mouse models of CAC were established with 2,4,6-Trinitrobenzenesulfonic acid (TNBS)and azoxymethane (AOM), following by biochemical, clinical and histological analysis. The integrity of epitheliumwas examined by electron microscopy (EM). The epithelial barrier function was evaluated with Ussing chamber. Real time PCR and fluorescent in situ hybridization (FISH) were performed to characterize the effect of C. butyricum on miR-200c; cell proliferation assays (MTT) were performed to study the role ofC. butyricum on epithelial cell proliferation mediated by miR-200c inhibitor; finally, we quantified the proinflammatory cytokines TNF-α and interleukin (IL)-12 by real time PCR. C. butyricum ameliorates clinical, histological and biochemical manifestations in colitis-induced CAC models. Further mechanistic studies demonstrated that C. Butyricum could lengthen epithelial microvillus and increase TER by decreasing the transepithelial permeability. We also showed that C. butyricum facilitates the expression of miR-200c, by which increase the proliferation rate. Finally, we found that C. butyricum can regulate the production of proinflammatory cytokines TNF-α and IL-12 through miR-200c. C. butyricum may regulate epithelial barrier function through miR-200c, then to be involved in the process of inflammation-associated cancers.

Corrigendum: Clostridium butyricum induces the production and glycosylation of mucins in HT-29 cells.

[This corrects the article DOI: 10.3389/fcimb.2021.668766.].

The effects of Clostridium butyricum on Ira rabbit growth performance, cecal microbiota and plasma metabolome.

Clostridium butyricum (C. butyricum) can provide many benefits for animals' growth performance and gut health. In this study, we investigated the effects of C. butyricum on the growth performance, cecal microbiota, and plasma metabolome in Ira rabbits. A total of 216 Ira rabbits at 32 days of age were randomly assigned to four treatments supplemented with basal diets containing 0 (CG), 200 (LC), 400 (MC), and 600 mg/kg (HC) C. butyricum for 35 days, respectively. In comparison with the CG group, C. butyricum supplementation significantly improved the average daily gain (ADG) and feed conversion rate (FCR) at 53 and 67 days of age (P < 0.05) and digestibilities of crude protein (CP) and crude fiber (CF) at 67 days of age (P < 0.05). The cellulase activity in the HC group was higher respectively by 50.14 and 90.13% at 53 and 67 days of age, than those in the CG groups (P < 0.05). Moreover, at 67 days of age, the diet supplemented with C. butyricum significantly increased the relative abundance of Verrucomicrobia at the phylum level (P < 0.05). Meanwhile, the concentrations of different metabolites, such as amino acids and purine, were significantly altered by C. butyricum (P < 0.05). In addition, 10 different genera were highly correlated with 52 different metabolites at 53-day-old and 6 different genera were highly correlated with 18 different metabolites at 67-day-old Ira rabbits. These findings indicated that the C. butyricum supplementation could significantly improve the growth performance by modifying the cecal microbiota structure and plasma metabolome of weaned Ira rabbits.

Clostridium butyricum alleviates dextran sulfate sodium-induced experimental colitis and promotes intestinal lymphatic vessel regeneration in mice.

Background: Inflammatory bowel disease (IBD) is the most common precancerous lesion of colitis-associated colon cancer (CAC). Studies have confirmed that pathological changes in intestinal lymphatic vessels (LVs) significantly promoted the development of IBD-associated carcinogenesis. An imbalance in the microecology of the intestinal flora is a key factor in the progression of IBD. As a result, therapeutic techniques that focus on the relationship between LV regeneration and flora management might be a potential treatment strategy. Methods: We investigated the role of Clostridium butyricum (C butyricum) in a dextran sulfate sodium (DSS)-induced IBD mouse model. Balb/c mice were given 3% DSS in their drinking water for 8 days to produce acute colitis and simultaneously administrated with C butyricum for 12 days. Hematoxylin and eosin (H&E) staining was used to evaluate the degree of colitis tissue damage. Levels of the lymphatic endothelial cell (LEC)-specific marker LYVE-1 and intestinal expressions of pro-lymphatic vascular endothelial growth factor (VEGF)-C and VEGF-D were determined using immunohistochemical assays. Results: In a DSS-induced IBD mouse model, we found that butyric acid-producing C butyricum significantly reduced disease activity index (DAI) scores in mice, reversed the shortening of the colon, weakened the degree of damage to colonic epithelial tissues, inhibited lymphocyte infiltration, and reduced pathological damage to the colon. To our knowledge, this is the first time that tissue expressions of LYVE-1, VEGF-C, and VEGF-D have been seen to increase in IBD-model mice after treatment with C butyricum. Conclusions: Our findings suggest that C butyricum might alleviate IBD in DSS-induced IBD-model mice by promoting intestinal LV regeneration.

Clostridium butyricum Induces the Production and Glycosylation of Mucins in HT-29 Cells.

C. butyricum is a common gut commensal bacterium, which has many positive functions in human intestine. In this study, we investigated the effects of monosaccharide and its derivatives on the adhesion of C. butyricum to the mucus of HT-29 cells. RNA interference was performed to assess the roles of MUC2 and glycan in the adhesion of C. butyricum to HT-29 cells. The effects of C. butyricum on the glycosylation of mucins were assayed with fluorescence microscope. The expression levels of mucins and glycotransferases were also determined. The results showed that C. butyricum could adhere to the mucins secreted by HT-29 cells. Several kinds of monosaccharides inhibited the adhesion of C. butyricum to HT-29 cells, which suggested that the mucus glycan was the attaching sites of this bacterium. Knockdown of MUC2, FUT2 or GALNT7 significantly decreased the numbers of the bacteria adhering to HT-29 cells. When colonizing on the surface of HT-29 cells, C. butyricum could increase the production of mucins, promote the expression of glycotransferase, and induce the glycosylation of mucins. These results demonstrated that the glycan of mucus played important roles in the adhesion of C. butyricum to HT-29 cells. This study indicates for the first time that C. butyricum possesses the ability to modulate the glycosylation profile of mucus secreted by HT-29 cells. These findings contribute to understanding the mechanism of interaction between colonic epithelial cells and commensal bacteria.

Effect of Dietary Clostridium butyricum Supplementation on Growth Performance, Intestinal Barrier Function, Immune Function, and Microbiota Diversity of Pekin Ducks.

Clostridium butyricum (C. butyricum) is increasingly being used to test the promotion of the gut health of animals. However, the modes of action for such applications for waterfowl remain unclear. Thus, we investigated whether or not intestinal barrier function, immune-related gene expression, and the diversity of the intestinal microbiota in Pekin ducks varied under C. butyricum supplementation. A total of 500 ducks were randomly assigned into five treatments supplemented with basal diets containing: either 0 (group Control), 200 (group CB200), 400 (group CB400) and 600 (group CB600) mg/kg C. butyricum or 150 mg/kg aureomycin (group A150) for 42 days. In comparison with the control group, C. butyricum supplementation enhanced the growth performance and intestinal villus height of Pekin ducks at 42 d. Serum immune indexes and fecal short-chain fatty acids (SCFAs) were all improved at both 21 d and 42 d after C. butyricum addition. The mRNA expression levels of Mucin2, Zonula occludens-1 (ZO-1), Caudin-3, and Occludin increased at 21 d and 42 d and the mRNA expression levels of IL-4 and IL-10 only increased at 42 d after C. butyricum addition. Dietary C. butyricum also resulted in an increase in the number of diversities of operational taxonomic units (OTUs), and an increase in the α-diversity of intestinal microbiota. The addition of C. butyricum altered the composition of the intestinal microbiota from 21 d to 42 d. The relative abundance of Firmicutes and Bacteroidetes showed little changes among groups; however, the relative abundance of Firmicutes/Bacteroidetes were found to have been significantly different between the 21 d and 42 d. C. butyricum administration improved the intestinal health of Pekin ducks by increasing the diversity of intestinal microbiota, enhancing the SCFAs contents, and strengthening the intestinal barrier function and immune systems. The optimal dietary supplementation dosage was recommended as 400 mg/kg in the diet.

Clostridium Butyricum ZJU-F1 Benefits the Intestinal Barrier Function and Immune Response Associated with Its Modulation of Gut Microbiota in Weaned Piglets.

This study investigated the effects of dietary C. butyricum ZJU-F1 on the apparent digestibility of nutrients, intestinal barrier function, immune response, and microflora of weaned piglets, with the aim of providing a theoretical basis for the application of Clostridium butyricum as an alternative to antibiotics in weaned piglets. A total of 120 weanling piglets were randomly divided into four treatment groups, in which piglets were fed a basal diet supplemented with antibiotics (CON), Bacillus licheniformis (BL), Clostridium butyricum ZJU-F1 (CB), or Clostridium butyricum and Bacillus licheniformis (CB-BL), respectively. The results showed that CB and CB-BL treatment increased the intestinal digestibility of nutrients, decreased intestinal permeability, and increased intestinal tight junction protein and mucin expression, thus maintaining the integrity of the intestinal epithelial barrier. CB and CB-BL, as exogenous probiotics, were also found to stimulate the immune response of weaned piglets and improve the expression of antimicrobial peptides in the ileum. In addition, dietary CB and CB-BL increased the proportion of Lactobacillus. The levels of butyric acid, propionic acid, acetic acid, and total acid were significantly increased in the ceca of piglets fed CB and CB-BL. Furthermore, we validated the effects of C. butyricum ZJU-F1 on the intestinal barrier function and immune response in vitro and found C. butyricum ZJU-F1 improved intestinal function and enhanced the TLR-2-MyD88-NF-κB signaling.

Clostridium butyricum Ameliorates Salmonella Enteritis Induced Inflammation by Enhancing and Improving Immunity of the Intestinal Epithelial Barrier at the Intestinal Mucosal Level.

This study was aimed to investigate the effects of Clostridium butyricum (C. butyricum) immunity and intestinal epithelial barrier function at the intestinal mucosal level, by using Salmonella enteritidis (S. enteritidis) to infect specific-pathogen-free (SPF) chickens and intestinal epithelial cells (IEC). We found that C. butyricum could decrease cytokine levels (IFN-γ, IL-1ß, IL-8, and TNF-α) via the TLR4-, MyD88-, and NF-κB-dependent pathways in intestinal tissues and intestinal epithelial cells. Additionally, C. butyricum could attenuate bacteria-induced intestinal damage and increase the expression level of muc-2 and ZO-1 in the intestine and intestinal epithelial cells. Furthermore, C. butyricum altered the intestinal microbial composition, increased the diversity of the bacterial communities in the cecum of Salmonella-infected chickens. In conclusion, C. butyricum effectively attenuated inflammation and epithelial barrier damage, altered the intestinal microbial composition, increased the diversity of the bacterial communities in the intestine of Salmonella-infected chickens. The result suggests that C. butyricum might be an effective and safe therapy for the treatment of Salmonella infection.

Effects of Different Probiotics on Laying Performance, Egg Quality, Oxidative Status, and Gut Health in Laying Hens.

With recent bans on the growth-promoting use of antibiotics, alternative strategies are needed to improve the performance of agricultural animals. Here, the effects of dietary supplementation with Clostridium butyricum and a combination of Saccharomyces boulardii and Pediococcus acidilactici were assessed on laying performance, egg quality, oxidative status, and gut health in laying hens. A total of 8208 Lohmann pink laying hens were divided into 3 treatment groups, with each group replicated 12 times (n = 228). Hens in the control group (CON) were provided a basic diet devoid of added antibiotics and probiotics. Treatment group 1 (T1) received the same base diet supplemented with 0.5 g/kg C. butyricum, and the diets of treatment group 2 (T2) supplemented with S. boulardii (0.05 g/kg) and P. acidilactici (0.1 g/kg) for the entirety of the 5-week trial. The data indicated that C. butyricum supplementation resulted in a significant reduction in ADFI, a significant increase in feed conversion, eggshell strength, and the CP% of albumen (dry matter, DM) relative to CON. The probiotic-treated hens exhibited decreased reactive oxygen species (ROS) levels in ileum and cecum, and reduced malondialdehyde (MDA) in serum. In conclusion, dietary supplementation with C. butyricum may be beneficial with respect to hen performance, egg quality, and gut health.

Single and Combined Effects of Clostridium butyricum and Saccharomyces cerevisiae on Growth Indices, Intestinal Health, and Immunity of Broilers.

A total of 120 1-day-old commercial Cobb chicks were used to study the effects of Clostridium butyricum (C. butyricum) and/or Saccharomyces cerevisiae (S. cerevisiae) on growth performance, intestinal health, and immune status in broilers. The experimental groups were as follows: G1; basal diet (BD), G2; basal diet (BD) plus C. butyricum preparation at 0.5 g/kg diet, G3; BD plus S. cerevisiae preparation at 0.5 g/kg diet, G4; BD plus 0.25 g/kg C. butyricum preparation plus 0.25 g/kg S. cerevisiae. Results showed that the total body weight gain, feed conversion efficiency, and protein efficiency ratio were significantly higher (p < 0.05) in the G4 group than in the other groups. The mortality percentage was reduced in the probiotic-supplemented groups. The villi height was elongated, and the villus height/crypt depth ratio was significantly increased in G2 and G4 chicks, compared to those in the control. The crypt depth was significantly decreased in all the probiotic-supplemented groups. Hemagglutination inhibition titers for Newcastle disease virus (NDV) were markedly increased in G2 and G4 chicks at 35 days of age, compared to those in G3 and control chicks. These results showed that dietary supplementation of a combined mixture of C. butyricum and S. cerevisiae in an equal ratio (G4) was more effective in improving growth performance, immune status, and gut health of broilers, compared with individual supplementation at a full dose.

Protection Mechanism of Clostridium butyricum against Salmonella Enteritidis Infection in Broilers.

This study was designed to evaluate the protection mechanism of oral administration of Clostridium butyricum against Salmonella enteritidis (SE) colonization in broilers. In the current study, 180 one-day-old healthy Arbor Acres (AA) broilers were meanly grouped into three, with three replicates of 20 birds each. An negative control group was fed basal diet without SE challenge and a positive control (PC) group was fed the basal diet and challenged with SE [106 colony forming unit (CFU)/0.2 mL]. An experimental (EXP) group was fed the basal diet, orally administered with C. butyricum (106 CFU/mL) and challenged with SE (106 CFU/0.2 mL). The results showed that compared to the PC group, the SE loads in livers, spleens, and cecal contents of chickens in EXP group were significantly reduced (P < 0.05) except in spleens at the 2-day post-infection; the production of interferon-γ, interleukin (IL)-1ß, IL-8, and tumor necrosis factor-α in the livers, spleens, and cecal tissues of chickens in EXP group were decreased to different extents. The results of quantitative real-time polymerase chain reaction further revealed that the inflammation of chickens in EXP group was alleviated by C. butyricum via down-regulating TLR4, MyD88, and NF-κB-dependent pathways. Collectively, these findings indicated that oral administration of C. butyricum could be a suitable alternative for preventing SE infection in broilers.

Biotechnological potential of Clostridium butyricum bacteria.

In response to demand from industry for microorganisms with auspicious biotechnological potential, a worldwide interest has developed in bacteria and fungi isolation. Microorganisms of interesting metabolic properties include non-pathogenic bacteria of the genus Clostridium, particularly C. acetobutylicum, C. butyricum and C. pasteurianum. A well-known property of C. butyricum is their ability to produce butyric acid, as well as effectively convert glycerol to 1,3-propanediol (38.2 g/L). A conversion rate of 0.66 mol 1,3-propanediol/mol of glycerol has been obtained. Results of the studies described in the present paper broaden our knowledge of characteristic features of C. butyricum specific isolates in terms of their phylogenetic affiliation, fermentation capacity and antibacterial properties.

An increasing of the efficiency of microbiological synthesis of 1, 3-propanediol from crude glycerol by the concentration of biomass

Background 1,3-Propanodiol (1,3-PD), is used in the production of polytrimethylene terephthalate (PTT), an aromatic polyester that exhibits high elastic recoveries. It is also employed as a supplement with low solidification properties, a solvent and a lubricant in the formof propylene glycol. 1,3-PD is effectively synthesized by a microbiological way from crude glycerol. The main problem of this technology is using a high concentration of glycerol, which is a limiting factor for bacteria cells growth (especially in batch fermentation). Results In this work, the influence of different glycerol concentration in batch fermentation on Clostridium butyricum DSP1 metabolism was investigated. The biomass was concentrated for two times with the use of membrane module (in case of increasing kinetic parameters). Increased optical density of bacteria cells six times increased the productivity of 1,3-PD in cultivation with 20 g/L of glycerol at the beginning of the process, and more than two times in cultivation with 60-80 g/L. Also the possibility of complete attenuation of 140 g/L of crude glycerol in the batch fermentation was investigated. During the cultivation, changes of protein profiles were analyzed. The most significant changes were observed in the cultivation in the medium supplemented with 80 g/L of glycerol. They related mainly to the DNA protein reconstructive systems, protective proteins (HSP), and also the enzymatic catalysts connected with glycerol metabolic pathway. Conclusions The application of filtration module in batch fermentation of crude glycerol by C. butyricum DSP1 significantly increased the productivity of the process.

Biotechnological potential of Clostridium butyricum bacteria

In response to demand from industry for microorganisms with auspicious biotechnological potential, a worldwide interest has developed in bacteria and fungi isolation. Microorganisms of interesting metabolic properties include non-pathogenic bacteria of the genus Clostridium, particularly C. acetobutylicum, C. butyricum and C. pasteurianum. A well-known property of C. butyricum is their ability to produce butyric acid, as well as effectively convert glycerol to 1,3-propanediol (38.2 g/L). A conversion rate of 0.66 mol 1,3-propanediol/mol of glycerol has been obtained. Results of the studies described in the present paper broaden our knowledge of characteristic features of C. butyricum specific isolates in terms of their phylogenetic affiliation, fermentation capacity and antibacterial properties.