The present study was taken up with a view to ascertain the possibility of introduction of alcohol resistant bacteria in vitro through the aseptically raised watermelon (Citrullus lanatus) seedlings in the backdrop of...The present study was taken up with a view to ascertain the possibility of introduction of alcohol resistant bacteria in vitro through the aseptically raised watermelon (Citrullus lanatus) seedlings in the backdrop of isolating such organisms from micropropagated watermelon stocks. Watermelon cv. Arka Manik seedlings grown in vitro from surface-sterilized seeds with the intact seed coat on MS medium appeared visibly clean largely, but upon subjecting them to tissue-indexing, the segments from the collar or root tissue showed bacterial colony growth on Nutrient Agar (NA) from 72% of such healthy seedlings and the cotyledon and hypocotyl tissue of 44% seedlings. The pooled colony growth from NA upon challenge with 90% alcohol yielded 10 distinct colony types, identified as B. pumilus (4×), B. subtilis (4×), B. cereus (1×) or B. safensis (1×) based on partial 16S rRNA sequence analysis. The shoot-tip tissue from the healthy index-negative seedlings cultured on watermelon proliferation medium partly turned index-positive within 2 - 4 sub-culture cycles while being apparently clean. On the other hand, those from the previously index-positive cultures tended to show obvious bacterial growth during subsequent in vitro culturing. The observations suggested the possibility of introduction of spore-forming Bacillus spp. through surface-sterilized seeds, their gradual emergence in vitro in visibly clean seedlings, possible transmittal of spores to the alcohol through tissue-culturing tools and the survival therein with the chances of unsuspected lateral spread. Seed coat removal followed by surface sterilization with sodium hypochlorite facilitated the raising of clean seedlings with no detectable bacterial association.展开更多
The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathoge...The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathogenic fungi with wide host plants, induced the mycelial morphological abnormalities, and decreased the sclerotoid production of Sclerotinia sclerotiorum in sealed plates. Spores of Botrytis cinerea exposed to these volatiles for 24-48 h in cavity slides cracked and the sporaceous inclusion became brown and effused to the suspension. An interesting phenomenon observed was that all the bacterial volatiles exhibited intense inhibitory activities against the pigment formation of tested pathogenic fungi, including Ascochyta citrullina, Alternaria solani, Alternaria brassicae, and so on. Interactions mediated by microbial volatiles could be widespread in soils, and volatiles may play an important role in reducing disease levels. A phylogenetic analysis based on 16S rDNA sequence placed the four bacteria in three species Paenibacillus polymyxa (BMP-11), Bacillus subtilis (BL02), and Bacillus pumilus (BSH-4 and ZB 13). Through headspace sampling and GC-MS analysis, a rich profile was found from B. subtilis and overlapping volatile patterns could be found among the different species. Studies are under the way to find the possible action mechanisms and to seek the effective application of bacterial volatiles in greenhouse.展开更多
Background:Previous research has shown that dietary supplementation of Bacillus spp.probiotics exerts beneficial effects on animals’growth.However,limited studies have evaluated the efficacy of Bacillus spp.on weaned...Background:Previous research has shown that dietary supplementation of Bacillus spp.probiotics exerts beneficial effects on animals’growth.However,limited studies have evaluated the efficacy of Bacillus spp.on weaned pigs and their effects on host gut health and microbiome,and systemic immunity using a disease challenge model.The objective of this experiment was to investigate the effects of two Bacillus spp.strains(Bacillus subtilis DSM 32540 and Bacillus pumilus DSM 32539)on growth performance,diarrhea,intestinal health,microbiome,and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC).Results:Pigs in PRO1(Bacillus subtilis DSM 32540)had greater(P<0.05)body weight on d 7 and 14 PI,greater(P<0.05)ADG from d 0 to 7 and d 7 to 14 PI,compared with pigs in CON(Control).Pigs in PRO1 had milder(P<0.05)diarrhea on d 2 and 3 PI compared with pigs in CON.However,no differences were observed in growth performance and diarrhea score between PRO2(Bacillus pumilus DSM 32539)and CON groups.Supplementation of PRO1 decreased(P<0.05)lymphocyte counts on d 7 and 14 PI,compared with CON.Supplementation of PRO1 and PRO2 both reduced(P<0.05)total coliforms in mesenteric lymph nodes on d 21 PI.Pigs in PRO2 had greater(P<0.05)goblet cell number and sulfomucin percentage in duodenal villi and greater(P<0.05)sialomucin percentage in jejunal villi than pigs in CON.Supplementation of PRO1 up-regulated(P<0.05)MUC2 gene expression in jejunal mucosa and reduced(P<0.05)PTGS-2 and IL1B gene expression in ileal mucosa on d 21 PI,compared with CON.Pigs in PRO1 had reduced(P<0.05)relative abundance of families Lachnospiraceae,Peptostreptococcaceae and Pasteurellaceae in the ileum.Conclusions:Supplementation of Bacillus subtilis DSM 32540 improved growth performance,alleviated diarrhea severity,enhanced gut health,and reduced systemic inflammation of weaned pigs infected with ETEC F18.Although Bacillus pumilus DSM 32539 was able to alleviate systemic inflammation,it had limited impacts on growth performance and severity of diarrhea of ETEC F18 challenged weaned pigs.展开更多
[ Objective] The paper was to screen the antagonistic Bacillus spp. strains against Phytophthora infestans (Mont.) de Bary and analyze its lipepeptide substances. [ Methods] Using flat isolation and culture method, ...[ Objective] The paper was to screen the antagonistic Bacillus spp. strains against Phytophthora infestans (Mont.) de Bary and analyze its lipepeptide substances. [ Methods] Using flat isolation and culture method, the bacteria that could produce Bacillus spp. were isolated from rhizosphere soil, and carried out primary and secondary screening by confrontation culture. The lipopeptide substances of Y-3 strain with better antifungal effect were carried out I-IPLC analysis. [Result] Nine strains of bacteria had certain antagonistic effects against P. infestans in primary screening, Y-1 and Y-3 strains had significant inhibition effect against the growth of P. infestans in secondary screening, with inhibition rate higher than 80% ; the crude extract of lipepeptide produced by Y-3 strain had better antagonistic effect against P. infestans, with inhibition rate higher than 90%. HPLC analysis showed that the crude extract of lipepeptide mainly contained 8 components. [ Conclusion] The lipopeptide substances produced by Y-3 strain had significant inhibition effect, which had potential application value for biological control of potato late blight.展开更多
In order to improve the spore yield of compound Bacillus spp. (B. amyloliquefaciens, B. laterosporus and B. megaterium), the effects of nutrient conditions including carbon source, nitrogen source, mineral salt and fe...In order to improve the spore yield of compound Bacillus spp. (B. amyloliquefaciens, B. laterosporus and B. megaterium), the effects of nutrient conditions including carbon source, nitrogen source, mineral salt and fermentation conditions including the inoculum age, inoculation amount, loading volume of liquid and initial pH on the spore yield were studied. The results indicated that the optimized medium was glucoses 20 g/L, soybean meal 30.0 g/L, K2HPO4 1.0 g/L;fermentation temperature is 37℃, the inoculum age 12 h, initial pH 7.0, 2% inoculation amount, loading volume of liquid 20 mL/250 mL. Under the optimized conditions of culture medium and fermentation for compound Bacillus spp., spore yield was 10.24 times more than the initial medium, and the spore formation rate reached more than 90%.展开更多
从冷冻菌种甘油管中分离到一株生长力极强的污染细菌,该细菌能产生抑制链格孢真菌的活性物质,在研究抑菌活性物质的过程中,对这株细菌进行分类鉴定.通过传统的表型及生理生化方法,将该菌定位到芽孢杆菌属(Bacillus),与枯草芽孢杆菌(B.su...从冷冻菌种甘油管中分离到一株生长力极强的污染细菌,该细菌能产生抑制链格孢真菌的活性物质,在研究抑菌活性物质的过程中,对这株细菌进行分类鉴定.通过传统的表型及生理生化方法,将该菌定位到芽孢杆菌属(Bacillus),与枯草芽孢杆菌(B.subtilis)的相似性最大,最终确定这株菌为B.subtilis中的一个株型,即Bacillus subtilis subsp.subtilis str.168.以链格孢属真菌(包括原有的和从空气、小麦病斑分离的)为受试菌,对此株细菌产生抑菌物质的时间进行跟踪,当该菌进入稳定生长期后开始产生抑菌物质,72 h时积累达到最大值.对抑菌物质进行过滤、加热、调节pH值等多种处理,初步确定抑菌物质的特性为外泌型、脂溶性,可透过孔径0.22μm的微孔滤膜,可耐受100℃5 m in,80℃10 m in的高温,微碱性条件不影响其生物活性.展开更多
Background: Bacillus spp. seem to be an alternative to antimicrobial growth promoters for improving animals' health and performance. However, there is little information on the effect of Bacillus spp. in combination...Background: Bacillus spp. seem to be an alternative to antimicrobial growth promoters for improving animals' health and performance. However, there is little information on the effect of Bacillus spp. in combination with different dietary crude protein(CP) levels on the ileal digestibility and microbiota composition. Therefore, the objective of this study was to determine the effect of Bacillus spp. supplementation to low-(LP) and high-protein diets(HP) on ileal CP and amino acid(AA) digestibility and intestinal microbiota composition.Methods: Eight ileally cannulated pigs with an initial body weight of 28.5 kg were randomly allocated to a rowcolumn design with 8 pigs and 3 periods of 16 d each. The assay diets were based on wheat-barley-soybean meal with two protein levels: LP(14% CP, as-fed) and HP diet(18% CP, as-fed). The LP and HP diets were supplemented with or without Bacil us spp. at a level of 0.04%(as-fed). The apparent ileal digestibility(AID) and standardized ileal digestibility(SID) of CP and AA was determined. Bacterial community composition from ileal digesta was analyzed by Illumina amplicon sequencing and quantitative real-time PCR. Data were analyzed as a 2 × 2 factorial design using the GLIMMIX procedures of SAS.Results: The supplementation with Bacillus spp. did not affect both AID and SID of CP and AA in growing pigs.Moreover, there was no difference in AID of CP and AA between HP and LP diets, but SID of cystine, glutamic acid,glycine, and proline was lower(P 〈 0.05) in pigs fed the HP diets. The HP diets increased abundance of Bifidobacterium spp. and Lactobacillus spp.,(P 〈 0.05) and by amplicon sequencing the latter was identified as predominant genus in microbiota from HP with Bacillus spp., whereas dietary supplementation of Bacillus spp. increased(P 〈 0.05) abundance of Roseburia spp.Conclusions: The HP diet increased abundance of Lactobacillus spp. and Bifidobacterium spp.. The supplementation of Bacil us spp. resulted in a higher abundance of healthy gut associated bacteria without affecting ileal CP and AA digestibility, whereas LP diet may reduce the flow of undigested protein to the large intestine of pigs.展开更多
With Fusarium oxysporum f.sp. phaseoli as the target bacterium,the bacterial strain with strong antagonistic activity was screened from crop rhizosphere soil using plate confrontation method and pot efficiency test. ...With Fusarium oxysporum f.sp. phaseoli as the target bacterium,the bacterial strain with strong antagonistic activity was screened from crop rhizosphere soil using plate confrontation method and pot efficiency test. This strain was identified according to morphological observation, physiological and biochemical characteristics and sequence analysis of 16S rRNA gene and gyrB gene. The results showed that LZF-5-3 strain was identified as Bacillus methylotrophicus and the control effect of LZF-5-3 against F.oxysporum in snap bean was 71.42% in pot test.展开更多
文摘The present study was taken up with a view to ascertain the possibility of introduction of alcohol resistant bacteria in vitro through the aseptically raised watermelon (Citrullus lanatus) seedlings in the backdrop of isolating such organisms from micropropagated watermelon stocks. Watermelon cv. Arka Manik seedlings grown in vitro from surface-sterilized seeds with the intact seed coat on MS medium appeared visibly clean largely, but upon subjecting them to tissue-indexing, the segments from the collar or root tissue showed bacterial colony growth on Nutrient Agar (NA) from 72% of such healthy seedlings and the cotyledon and hypocotyl tissue of 44% seedlings. The pooled colony growth from NA upon challenge with 90% alcohol yielded 10 distinct colony types, identified as B. pumilus (4×), B. subtilis (4×), B. cereus (1×) or B. safensis (1×) based on partial 16S rRNA sequence analysis. The shoot-tip tissue from the healthy index-negative seedlings cultured on watermelon proliferation medium partly turned index-positive within 2 - 4 sub-culture cycles while being apparently clean. On the other hand, those from the previously index-positive cultures tended to show obvious bacterial growth during subsequent in vitro culturing. The observations suggested the possibility of introduction of spore-forming Bacillus spp. through surface-sterilized seeds, their gradual emergence in vitro in visibly clean seedlings, possible transmittal of spores to the alcohol through tissue-culturing tools and the survival therein with the chances of unsuspected lateral spread. Seed coat removal followed by surface sterilization with sodium hypochlorite facilitated the raising of clean seedlings with no detectable bacterial association.
基金the National Key Technology R&D Program of China (2006BAD08A03)the Shandong Agricultural University Postdoctoral Foundation (200603065)
文摘The four effective antagonistic Bacillus strains, isolated from the rhizosphere soil of cucumber in a greenhouse, produced antifungal volatiles. These volatiles strongly inhibited the growth of the most tested pathogenic fungi with wide host plants, induced the mycelial morphological abnormalities, and decreased the sclerotoid production of Sclerotinia sclerotiorum in sealed plates. Spores of Botrytis cinerea exposed to these volatiles for 24-48 h in cavity slides cracked and the sporaceous inclusion became brown and effused to the suspension. An interesting phenomenon observed was that all the bacterial volatiles exhibited intense inhibitory activities against the pigment formation of tested pathogenic fungi, including Ascochyta citrullina, Alternaria solani, Alternaria brassicae, and so on. Interactions mediated by microbial volatiles could be widespread in soils, and volatiles may play an important role in reducing disease levels. A phylogenetic analysis based on 16S rDNA sequence placed the four bacteria in three species Paenibacillus polymyxa (BMP-11), Bacillus subtilis (BL02), and Bacillus pumilus (BSH-4 and ZB 13). Through headspace sampling and GC-MS analysis, a rich profile was found from B. subtilis and overlapping volatile patterns could be found among the different species. Studies are under the way to find the possible action mechanisms and to seek the effective application of bacterial volatiles in greenhouse.
基金supported by Evonik Nutrition&Care GmbH,Germany and the United States Department of Agriculture(USDA)National Institute of Food and Agriculture,multistate project W400。
文摘Background:Previous research has shown that dietary supplementation of Bacillus spp.probiotics exerts beneficial effects on animals’growth.However,limited studies have evaluated the efficacy of Bacillus spp.on weaned pigs and their effects on host gut health and microbiome,and systemic immunity using a disease challenge model.The objective of this experiment was to investigate the effects of two Bacillus spp.strains(Bacillus subtilis DSM 32540 and Bacillus pumilus DSM 32539)on growth performance,diarrhea,intestinal health,microbiome,and systemic immunity of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli(ETEC).Results:Pigs in PRO1(Bacillus subtilis DSM 32540)had greater(P<0.05)body weight on d 7 and 14 PI,greater(P<0.05)ADG from d 0 to 7 and d 7 to 14 PI,compared with pigs in CON(Control).Pigs in PRO1 had milder(P<0.05)diarrhea on d 2 and 3 PI compared with pigs in CON.However,no differences were observed in growth performance and diarrhea score between PRO2(Bacillus pumilus DSM 32539)and CON groups.Supplementation of PRO1 decreased(P<0.05)lymphocyte counts on d 7 and 14 PI,compared with CON.Supplementation of PRO1 and PRO2 both reduced(P<0.05)total coliforms in mesenteric lymph nodes on d 21 PI.Pigs in PRO2 had greater(P<0.05)goblet cell number and sulfomucin percentage in duodenal villi and greater(P<0.05)sialomucin percentage in jejunal villi than pigs in CON.Supplementation of PRO1 up-regulated(P<0.05)MUC2 gene expression in jejunal mucosa and reduced(P<0.05)PTGS-2 and IL1B gene expression in ileal mucosa on d 21 PI,compared with CON.Pigs in PRO1 had reduced(P<0.05)relative abundance of families Lachnospiraceae,Peptostreptococcaceae and Pasteurellaceae in the ileum.Conclusions:Supplementation of Bacillus subtilis DSM 32540 improved growth performance,alleviated diarrhea severity,enhanced gut health,and reduced systemic inflammation of weaned pigs infected with ETEC F18.Although Bacillus pumilus DSM 32539 was able to alleviate systemic inflammation,it had limited impacts on growth performance and severity of diarrhea of ETEC F18 challenged weaned pigs.
基金Supported by Natural Science Foundation of Hebei Province( C2011201003)
文摘[ Objective] The paper was to screen the antagonistic Bacillus spp. strains against Phytophthora infestans (Mont.) de Bary and analyze its lipepeptide substances. [ Methods] Using flat isolation and culture method, the bacteria that could produce Bacillus spp. were isolated from rhizosphere soil, and carried out primary and secondary screening by confrontation culture. The lipopeptide substances of Y-3 strain with better antifungal effect were carried out I-IPLC analysis. [Result] Nine strains of bacteria had certain antagonistic effects against P. infestans in primary screening, Y-1 and Y-3 strains had significant inhibition effect against the growth of P. infestans in secondary screening, with inhibition rate higher than 80% ; the crude extract of lipepeptide produced by Y-3 strain had better antagonistic effect against P. infestans, with inhibition rate higher than 90%. HPLC analysis showed that the crude extract of lipepeptide mainly contained 8 components. [ Conclusion] The lipopeptide substances produced by Y-3 strain had significant inhibition effect, which had potential application value for biological control of potato late blight.
文摘In order to improve the spore yield of compound Bacillus spp. (B. amyloliquefaciens, B. laterosporus and B. megaterium), the effects of nutrient conditions including carbon source, nitrogen source, mineral salt and fermentation conditions including the inoculum age, inoculation amount, loading volume of liquid and initial pH on the spore yield were studied. The results indicated that the optimized medium was glucoses 20 g/L, soybean meal 30.0 g/L, K2HPO4 1.0 g/L;fermentation temperature is 37℃, the inoculum age 12 h, initial pH 7.0, 2% inoculation amount, loading volume of liquid 20 mL/250 mL. Under the optimized conditions of culture medium and fermentation for compound Bacillus spp., spore yield was 10.24 times more than the initial medium, and the spore formation rate reached more than 90%.
文摘从冷冻菌种甘油管中分离到一株生长力极强的污染细菌,该细菌能产生抑制链格孢真菌的活性物质,在研究抑菌活性物质的过程中,对这株细菌进行分类鉴定.通过传统的表型及生理生化方法,将该菌定位到芽孢杆菌属(Bacillus),与枯草芽孢杆菌(B.subtilis)的相似性最大,最终确定这株菌为B.subtilis中的一个株型,即Bacillus subtilis subsp.subtilis str.168.以链格孢属真菌(包括原有的和从空气、小麦病斑分离的)为受试菌,对此株细菌产生抑菌物质的时间进行跟踪,当该菌进入稳定生长期后开始产生抑菌物质,72 h时积累达到最大值.对抑菌物质进行过滤、加热、调节pH值等多种处理,初步确定抑菌物质的特性为外泌型、脂溶性,可透过孔径0.22μm的微孔滤膜,可耐受100℃5 m in,80℃10 m in的高温,微碱性条件不影响其生物活性.
基金financially supported by Chr.Hansen A/S(Horsholm,Denmark)the Foundation fiat panis(Ulm,Germany)+1 种基金a scholarship for Chanwit Kaewtapee granted by Food Security Center(FSC)University of Hohenheim under the German Academic Exchange Service(DAAD)program exceed with funds of the Federal Ministry for Economic Cooperation and Development(BMZ)of Germany
文摘Background: Bacillus spp. seem to be an alternative to antimicrobial growth promoters for improving animals' health and performance. However, there is little information on the effect of Bacillus spp. in combination with different dietary crude protein(CP) levels on the ileal digestibility and microbiota composition. Therefore, the objective of this study was to determine the effect of Bacillus spp. supplementation to low-(LP) and high-protein diets(HP) on ileal CP and amino acid(AA) digestibility and intestinal microbiota composition.Methods: Eight ileally cannulated pigs with an initial body weight of 28.5 kg were randomly allocated to a rowcolumn design with 8 pigs and 3 periods of 16 d each. The assay diets were based on wheat-barley-soybean meal with two protein levels: LP(14% CP, as-fed) and HP diet(18% CP, as-fed). The LP and HP diets were supplemented with or without Bacil us spp. at a level of 0.04%(as-fed). The apparent ileal digestibility(AID) and standardized ileal digestibility(SID) of CP and AA was determined. Bacterial community composition from ileal digesta was analyzed by Illumina amplicon sequencing and quantitative real-time PCR. Data were analyzed as a 2 × 2 factorial design using the GLIMMIX procedures of SAS.Results: The supplementation with Bacillus spp. did not affect both AID and SID of CP and AA in growing pigs.Moreover, there was no difference in AID of CP and AA between HP and LP diets, but SID of cystine, glutamic acid,glycine, and proline was lower(P 〈 0.05) in pigs fed the HP diets. The HP diets increased abundance of Bifidobacterium spp. and Lactobacillus spp.,(P 〈 0.05) and by amplicon sequencing the latter was identified as predominant genus in microbiota from HP with Bacillus spp., whereas dietary supplementation of Bacillus spp. increased(P 〈 0.05) abundance of Roseburia spp.Conclusions: The HP diet increased abundance of Lactobacillus spp. and Bifidobacterium spp.. The supplementation of Bacil us spp. resulted in a higher abundance of healthy gut associated bacteria without affecting ileal CP and AA digestibility, whereas LP diet may reduce the flow of undigested protein to the large intestine of pigs.
文摘With Fusarium oxysporum f.sp. phaseoli as the target bacterium,the bacterial strain with strong antagonistic activity was screened from crop rhizosphere soil using plate confrontation method and pot efficiency test. This strain was identified according to morphological observation, physiological and biochemical characteristics and sequence analysis of 16S rRNA gene and gyrB gene. The results showed that LZF-5-3 strain was identified as Bacillus methylotrophicus and the control effect of LZF-5-3 against F.oxysporum in snap bean was 71.42% in pot test.