Plasma-activated water(PAW) indicated promising potential in controlling the biological contamination of Bacillus cereus,which eliminated its evolutionary endospore that improves its survival ability.However,the spore...Plasma-activated water(PAW) indicated promising potential in controlling the biological contamination of Bacillus cereus,which eliminated its evolutionary endospore that improves its survival ability.However,the spore inactivation mechanism by PAW at molecular level was not well understood.The mechanism of the B.cereus endospore against PAW at proteomic levels was demonstrated.The Tandem Mass Tag(TMT) labeling was performed.By comparing the treatment groups with control(including PAW and PAW added superoxide dismutase(SOD)),the expression of 251 proteins(with the number of 207 up-and 44 down-regulated) and 379 proteins(with the corresponding number of 238 and 141) were drastically affected,separately.The 6 categories based on the protein-protein interaction(PPI) networks included oxidation-reduction,transport,sporulation and DNA topological change,gene expression,metabolism,and others.The 3 dehydrogenases(genes hisD,BC_2176,and asd) in PAW while oxidoreductase(genes BC_0399 and BC_2529) in SOD were activated to maintain the antioxidation of spores.The proteins(BC_4271 and BC_2655) in SOD were dramatically activated,which were involved in the carbohydrate,amino acid,and energy-coupling transport.All the small,acid-soluble spore proteins were activated in both groups to protect the spores' DNA.In SOD,genes metG2 and rpmC also were considered important factors in translation while this role was played in gene groES but not rpmF in PAW.The PAW activated the biogenesis of cell wall/membrane/envelope and phosphorelay signal transduction system to contribute to the survival of spores whereas the SOD damaged these 2 processes as well as cell division,chromosome separation,organic acid phosphorylation,base-and nucleotide-excision repairs to lead to the death of spores.This would promise to lay the foundation for advancing the study of the intrinsic mechanism of spore killing against PAW and can also provide a reference for future verification.展开更多
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
基金supported by the Zhejiang Provincial Natural Science Foundation of China (LR21C200002)。
文摘Plasma-activated water(PAW) indicated promising potential in controlling the biological contamination of Bacillus cereus,which eliminated its evolutionary endospore that improves its survival ability.However,the spore inactivation mechanism by PAW at molecular level was not well understood.The mechanism of the B.cereus endospore against PAW at proteomic levels was demonstrated.The Tandem Mass Tag(TMT) labeling was performed.By comparing the treatment groups with control(including PAW and PAW added superoxide dismutase(SOD)),the expression of 251 proteins(with the number of 207 up-and 44 down-regulated) and 379 proteins(with the corresponding number of 238 and 141) were drastically affected,separately.The 6 categories based on the protein-protein interaction(PPI) networks included oxidation-reduction,transport,sporulation and DNA topological change,gene expression,metabolism,and others.The 3 dehydrogenases(genes hisD,BC_2176,and asd) in PAW while oxidoreductase(genes BC_0399 and BC_2529) in SOD were activated to maintain the antioxidation of spores.The proteins(BC_4271 and BC_2655) in SOD were dramatically activated,which were involved in the carbohydrate,amino acid,and energy-coupling transport.All the small,acid-soluble spore proteins were activated in both groups to protect the spores' DNA.In SOD,genes metG2 and rpmC also were considered important factors in translation while this role was played in gene groES but not rpmF in PAW.The PAW activated the biogenesis of cell wall/membrane/envelope and phosphorelay signal transduction system to contribute to the survival of spores whereas the SOD damaged these 2 processes as well as cell division,chromosome separation,organic acid phosphorylation,base-and nucleotide-excision repairs to lead to the death of spores.This would promise to lay the foundation for advancing the study of the intrinsic mechanism of spore killing against PAW and can also provide a reference for future verification.
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.
