Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment.Bio-sorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and...Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment.Bio-sorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and alternative technology for removal of these pollutants from aqueous solution.The search of marine actinobacteria with potential heavy metal biosorption ability resulted in the identification of a novel alkalophilic Streptomyces VITSVK5 species.The biosorption property of Streptomyces VITSVK5 spp.was investigated by absorbing heavy metals Cadmium (Cd) and Lead (Pb).Physiochemical characteristics and trace metal concentration analysis of the backwater showed the concentrations of different metals were lead 13±2.1 μg L-1,cadmium 3.1±0.3μg L-1,zinc 8.4±2.6μg L-1 and copper 0.3±0.1μg L-1,whereas mercury was well below the detection limit.The effect of pH and biomass dosage on removal efficiency of heavy metal ions was also investigated.The optimum pH for maximal biosorption was 4.0 for Cd (II) and 5.0 for Pb (II) with 41% and 84% biosorption respectively.The biosorbent dosage was optimized as 3 g L-1 for both the trace metals.Fourier transform infrared absorption spectrum results indicated the chemical interactions of hydrogen atoms in carboxyl (–COOH),hydroxyl (–CHOH) and amine (–NH2) groups of biomass with the metal ions.This could be mainly involved in the biosorption of Cd (II) and Pb (II) onto Streptomyces VITSVK5 spp.The results of our study revealed Streptomyces metabolites could be used to develop a biosorbent for adsorbing metal ions from aqueous environments.展开更多
Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms ...Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms of Fragaria spp. from January 2021 to February 2022. The plant was introduced in Cameroon in 2018. There are 13 varieties of Fragaria spp. currently cultivated. Among these 13 varieties, eleven are hybrids of Fragaria x ananassa (“Amiga”, “Amine”, “Camarosa”, “Chandler”, “Charlotte”, “Elsanta”, “Gariguette”, “Madame Moutot”, “Ostara”, “Ruby gem” and “San Andreas”), and two of the hybrids of Fragaria vesca (“Maestro” and “Mara des bois”). The cropping system, irrigation system, and type of fertilizers applied differ from one strawberry farm to another. Biofertilizers (such as mycorrhizal), inorganic and organic fertilizers are actually used to improve production. The potential annual production of strawberries from January 2021 to February 2022, estimated based on the survey data, was 21.216 tons for all growers. Among these eight production farms, the Lolodorf BIO Farm presents 6000 kg (six tons) of strawberries and 100,000 stolons (seedlings) produced, from seven varieties of Fragaria spp. cultivated, with 6 varieties which are hybrids variety Fragaria x ananassa (“Amiga”, “Amine”, “Chandler”, “Gariguette”, “Madame Moutot”, and “Ruby gem”), and one which is a hybrid of Fragaria vesca (“Mara des bois”). Certain diseases were also observed and recorded depending on the growing areas.展开更多
Bacteria of the genus Vibrio are ubiquitously distributed in the marine environment. Due to the rapid expansion of intensive mariculture and the consequent deterioration of culture conditions, more and more Vibrio spp...Bacteria of the genus Vibrio are ubiquitously distributed in the marine environment. Due to the rapid expansion of intensive mariculture and the consequent deterioration of culture conditions, more and more Vibrio spp. have been recognized as pathogenic agents in outbreaks of vibriosis, a serious epizootic disease affecting most wild and farmed fish species worldwide, which has become the most important limiting factor for the development of intensive mariculture industry. Attempts have been made to understand the pathogenicity of vibrios in host fish with the ultimate aim of elucidating the best means for disease control. After an extensive literature survey of the recent advances in the field of fish vibriosis, the pathological changes, virulence factors and associated potential pathogenic mechanisms, transmission routes and related environmental factors involved in outbreak of vibriosis, as well as the controlling strategies are reviewed in the present paper.展开更多
The antifungal activity and toxicity of new type polyene macrolide antibiotics-Antifungalmycin 702 and Fungichromin against Rhizoctonia solani, Hel- minthosporium sigmoideum Car. , Magnaporthe grisea and Ustilaginoide...The antifungal activity and toxicity of new type polyene macrolide antibiotics-Antifungalmycin 702 and Fungichromin against Rhizoctonia solani, Hel- minthosporium sigmoideum Car. , Magnaporthe grisea and Ustilaginoidea virens were studied by mycelial growth rate method and mycelial dry weight method in vitro. The results showed that both of Antifungalmycin 702 and Fungichromin had strong antifungal activity against four speices of rice pathogenic fungi. Treated with 50 μmL Antifungalmycin 702 , the inhibitory rates of Antifungalmycin 702 agmnst R. solani, H. sigmoideum Cav., M. grisea and U. virens were 100%, 100%,91.20% and 68.10%, and EC50 and ECho were 7.00, 10.30, 14.41, 26.71 and 13.20, 17.66, 27.67,128.28 p.g/mL, respectively. Treated with 13 pg/mL Fungichremln, the inhibitory rates of Fungichromin against four speices of rice pathogenic fungi were 78.20%, 100%, 100% and 79.17%, and ECs0 and ECg0 were 1.47, 1.91, 2.37, 0. 20 and 41. （15, 3.92, 4.34, 135.54 gg/mL, respectively. The antifungal activity of Fungichromin was stronger than Antifungalmycin 702.展开更多
The dichloromethane extract of culture filtrate from Streptomyces aburaviensis R9 was evaluated using various rapid bioassays to determine potential inhibitory effects towards phytopathogenic fungi (Colletotrichum acu...The dichloromethane extract of culture filtrate from Streptomyces aburaviensis R9 was evaluated using various rapid bioassays to determine potential inhibitory effects towards phytopathogenic fungi (Colletotrichum acutatum, C. fragariae, C. gloeosoprioids, Botrytis cinerea, Fusarium oxysporum, Phomopsis viticola and P. obscurans), fish bacterial pathogens (Edwardsiella ictaluri and Flavobacterium columnare), a green alga (Selenastrum capricornutum), plant seeds [Bent grass (Agrostis sp.) monocot and lettuce (Lactuca sativa) dicot] and 2-methylisoborneol (MIB)-producing cyanobacteria (Planktothrix perornata and Pseudanabaena sp.). The dichloromethane extract showed selective inhibition against the cyanobacterium P. perornata, with a lowest-complete-inhibition concentration (LCIC) of 10 mg/L and lowest-observed-effect concentration (LOEC) of 10 mg/L while LCIC and LOEC values were 100 mg/L when tested against S. capricornutum. This extract also showed slight meristematic cytogenic necrosis at 200 mg/L towards germinated seeds of both test plants. The compounds were not very toxic towards the channel catfish (Ictalurus punctatus) pathogenic bacteria E. ictaluri and F. columnare. Preliminary evaluation of the extract toward C. acutatum, C. fragariae and C. gloeosoprioids using TLC bioautography revealed moderate activity. However, further evaluation of the extract using a microtiter plate bioassay determined that inhibition was strongest against C. acutatum and C. fragariae, though this inhibitory activity diminished at 72 hours and was moderately less active than the commercial fungicides azoxystrobin and captan when comparing 1 - 100 mg/L levels at 48 hours.展开更多
Prema 178 onion variety is widely used in production in Burkina Faso. It is greatly appreciated but susceptible to basal rot. This study aimed to evaluate the pathogenic ability of six strains of Fusarium genus identi...Prema 178 onion variety is widely used in production in Burkina Faso. It is greatly appreciated but susceptible to basal rot. This study aimed to evaluate the pathogenic ability of six strains of Fusarium genus identified in Burkina Faso on onion. Seeds, seedlings and bulbs were used for the test. A conidial suspension of each strain was made in tubes and adjusted to 1 × 10<sup>6</sup> conidia/ml with distilled water for the different tests. Germination test in the laboratory and greenhouse showed that all treatments with the strains of Fusarium oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, F. proliferatum and F. sp. induced failure to emerge and showed a significant difference with the control. The different strains also induced stunting rates of coleoptile growth. Fusarium oxysporum f. sp. cepae, F. acutatum, F. proliferatum, F. falciforme and F. solani were very aggressive, as they recorded above 50% damping-off rates. The test on the bulbs revealed that the strains were classified into two groups. The first consists of F. oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, which caused rots with respective lengths from 2.06;1.48;1.84;1.46 and 2.12 cm, thus very aggressive according to Ghanbarzadeh scale. The second is formed by F. proliferatum which recorded 0.90 cm of rot length, thus moderately aggressive. It would be appropriate to suggest a sustainable management method for these pathogens in order to improve the yield of onion production.展开更多
目的为了解不同来源的人类条件病原体的特征和耐药机制,预防环境病原体和医院病原体交叉感染,对桑树中分离的克雷伯菌进行耐药性、毒力基因、分子分型特点的探究。方法从广东和广西两地采集桑树和桑树根际土壤样本,其中共分离得到12株...目的为了解不同来源的人类条件病原体的特征和耐药机制,预防环境病原体和医院病原体交叉感染,对桑树中分离的克雷伯菌进行耐药性、毒力基因、分子分型特点的探究。方法从广东和广西两地采集桑树和桑树根际土壤样本,其中共分离得到12株克雷伯菌,对其采用纸片扩散法(K-B法)检测菌株耐药性表征;采用PCR技术对6类9个抗生素相关耐药基因和毒力基因进行检测;采用多位点序列分型(multilocus sequence typing,MLST)技术进行遗传分析。结果12株桑源克雷伯菌检测到bla_(SHV)、tet(D)、tet(A)和aadA14种耐药基因,其中携带氨基糖苷类相关基因aadA1的有5株(41.67%);12株桑源克雷伯菌均对氨基糖苷类抗生素红霉素和链霉素表现出耐药,对6种以上抗生素耐药的菌株有6株(50%),对7种抗生素耐药的菌株有2株(16.67%);8株(66.67%)携带脂多糖相关的wabG毒力基因;MLST分析显示12株桑源克雷伯菌划分为3大类,包括产酸克雷伯菌复合体(Klebsiella oxytoca species complex,KoSC)、肺炎克雷伯菌复合体(K.pneumoniae species complex,KpSC)以及产气克雷伯菌(K.aerogenes);可分成7个序列型(sequence typing,ST),ST260为优势序列型,有5株(41.67%)。结论12株桑源克雷伯菌对氨基糖苷类抗生素耐药情况严峻,氨基糖苷类aadA1耐药基因检出率最高;ST260是主要的序列型,菌株之间存在遗传多样性,为环境中桑树来源的克雷伯菌病原体致病机制提供理论依据。展开更多
The fungal community associated with beach sand and plants located along marine coasts are an under-studied area of research despite its potential relevance to human health. In this study, we isolated and identified t...The fungal community associated with beach sand and plants located along marine coasts are an under-studied area of research despite its potential relevance to human health. In this study, we isolated and identified the cultivable mycobiota associated with sand and plants collected along the coast of Gran Canaria (Spain) using culture-dependent and -independent methods. Clinically relevant species belonging to Cryptococcus spp. and related genera such as Naganishia and Papilotrema were isolated and identified from shoreline plants. Moreover, Candida tropicalis was isolated from beach sand, and Aspergillus fumigatus and Aspergillus terreus strains were associated with both types of samples (i.e., plants and beach sand). We conclude that beach sand and shoreline plants are potential reservoirs of fungi of high clinical interest. We recommend including beach sand and plants from the environment when assessing the quality of marine coastal systems. Our results open a framework for studying the natural marine environment and its role in the epidemiology of infectious diseases in order to more accurately manage public health.展开更多
To provide a scientific basis for controlling mulberry bacterial blight in Bazhong,Sichuan,China(BSC),this study aimed to isolate and purify pathogenic bacteria from diseased branches of mulberry trees in the region a...To provide a scientific basis for controlling mulberry bacterial blight in Bazhong,Sichuan,China(BSC),this study aimed to isolate and purify pathogenic bacteria from diseased branches of mulberry trees in the region and to clarify their taxonomic status using morphological observation,physiological and biochemical detection,molecular-level identification,and the construction of a phylogenetic tree.A total of 218 bacterial strains were isolated from samples of diseased mulberry branches.Of these,7 strains were identified as pathogenic bacteria based on pathogenicity tests conducted in accordance with Koch’s postulates.Preliminary findings from the analysis of the 16S rRNA sequence indicated that the 7 pathogenic bacteria are members of Klebsiella spp.Morphological observation revealed that the pathogenic bacteria were oval-shaped and had capsules but no spores.They could secrete pectinase,cellulase,and protease and were able to utilize D-glucose,D-mannose,D-maltose,and D-Cellobiose.The 7 strains of pathogenic bacteria exhibited the highest homology with Klebsiella oxytoca.This study identifies Klebsiella oxytoca as the causative agent of mulberry bacterial blight in BSC,laying the foundation for the prevention and control of this pathogen and further investigation into its pathogenic mechanism.展开更多
文摘Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment.Bio-sorption of heavy metals by metabolically inactive biomass of microbial organisms is an innovative and alternative technology for removal of these pollutants from aqueous solution.The search of marine actinobacteria with potential heavy metal biosorption ability resulted in the identification of a novel alkalophilic Streptomyces VITSVK5 species.The biosorption property of Streptomyces VITSVK5 spp.was investigated by absorbing heavy metals Cadmium (Cd) and Lead (Pb).Physiochemical characteristics and trace metal concentration analysis of the backwater showed the concentrations of different metals were lead 13±2.1 μg L-1,cadmium 3.1±0.3μg L-1,zinc 8.4±2.6μg L-1 and copper 0.3±0.1μg L-1,whereas mercury was well below the detection limit.The effect of pH and biomass dosage on removal efficiency of heavy metal ions was also investigated.The optimum pH for maximal biosorption was 4.0 for Cd (II) and 5.0 for Pb (II) with 41% and 84% biosorption respectively.The biosorbent dosage was optimized as 3 g L-1 for both the trace metals.Fourier transform infrared absorption spectrum results indicated the chemical interactions of hydrogen atoms in carboxyl (–COOH),hydroxyl (–CHOH) and amine (–NH2) groups of biomass with the metal ions.This could be mainly involved in the biosorption of Cd (II) and Pb (II) onto Streptomyces VITSVK5 spp.The results of our study revealed Streptomyces metabolites could be used to develop a biosorbent for adsorbing metal ions from aqueous environments.
文摘Strawberry (Fragaria spp.) is one of the most important fruits classified as exotic fruits imported into Cameroon. To have an inventory of its cultivation in Cameroon, a survey study was carried out among eight farms of Fragaria spp. from January 2021 to February 2022. The plant was introduced in Cameroon in 2018. There are 13 varieties of Fragaria spp. currently cultivated. Among these 13 varieties, eleven are hybrids of Fragaria x ananassa (“Amiga”, “Amine”, “Camarosa”, “Chandler”, “Charlotte”, “Elsanta”, “Gariguette”, “Madame Moutot”, “Ostara”, “Ruby gem” and “San Andreas”), and two of the hybrids of Fragaria vesca (“Maestro” and “Mara des bois”). The cropping system, irrigation system, and type of fertilizers applied differ from one strawberry farm to another. Biofertilizers (such as mycorrhizal), inorganic and organic fertilizers are actually used to improve production. The potential annual production of strawberries from January 2021 to February 2022, estimated based on the survey data, was 21.216 tons for all growers. Among these eight production farms, the Lolodorf BIO Farm presents 6000 kg (six tons) of strawberries and 100,000 stolons (seedlings) produced, from seven varieties of Fragaria spp. cultivated, with 6 varieties which are hybrids variety Fragaria x ananassa (“Amiga”, “Amine”, “Chandler”, “Gariguette”, “Madame Moutot”, and “Ruby gem”), and one which is a hybrid of Fragaria vesca (“Mara des bois”). Certain diseases were also observed and recorded depending on the growing areas.
文摘Bacteria of the genus Vibrio are ubiquitously distributed in the marine environment. Due to the rapid expansion of intensive mariculture and the consequent deterioration of culture conditions, more and more Vibrio spp. have been recognized as pathogenic agents in outbreaks of vibriosis, a serious epizootic disease affecting most wild and farmed fish species worldwide, which has become the most important limiting factor for the development of intensive mariculture industry. Attempts have been made to understand the pathogenicity of vibrios in host fish with the ultimate aim of elucidating the best means for disease control. After an extensive literature survey of the recent advances in the field of fish vibriosis, the pathological changes, virulence factors and associated potential pathogenic mechanisms, transmission routes and related environmental factors involved in outbreak of vibriosis, as well as the controlling strategies are reviewed in the present paper.
基金Supported by National Natural Science Foundation of China(30960011 and 31071724) Natural Science Foundation of Jiangxi Province (2009GZN0030)Science and Technology Support Program of Jiangxi Province(2007BN14002)
文摘The antifungal activity and toxicity of new type polyene macrolide antibiotics-Antifungalmycin 702 and Fungichromin against Rhizoctonia solani, Hel- minthosporium sigmoideum Car. , Magnaporthe grisea and Ustilaginoidea virens were studied by mycelial growth rate method and mycelial dry weight method in vitro. The results showed that both of Antifungalmycin 702 and Fungichromin had strong antifungal activity against four speices of rice pathogenic fungi. Treated with 50 μmL Antifungalmycin 702 , the inhibitory rates of Antifungalmycin 702 agmnst R. solani, H. sigmoideum Cav., M. grisea and U. virens were 100%, 100%,91.20% and 68.10%, and EC50 and ECho were 7.00, 10.30, 14.41, 26.71 and 13.20, 17.66, 27.67,128.28 p.g/mL, respectively. Treated with 13 pg/mL Fungichremln, the inhibitory rates of Fungichromin against four speices of rice pathogenic fungi were 78.20%, 100%, 100% and 79.17%, and ECs0 and ECg0 were 1.47, 1.91, 2.37, 0. 20 and 41. （15, 3.92, 4.34, 135.54 gg/mL, respectively. The antifungal activity of Fungichromin was stronger than Antifungalmycin 702.
文摘The dichloromethane extract of culture filtrate from Streptomyces aburaviensis R9 was evaluated using various rapid bioassays to determine potential inhibitory effects towards phytopathogenic fungi (Colletotrichum acutatum, C. fragariae, C. gloeosoprioids, Botrytis cinerea, Fusarium oxysporum, Phomopsis viticola and P. obscurans), fish bacterial pathogens (Edwardsiella ictaluri and Flavobacterium columnare), a green alga (Selenastrum capricornutum), plant seeds [Bent grass (Agrostis sp.) monocot and lettuce (Lactuca sativa) dicot] and 2-methylisoborneol (MIB)-producing cyanobacteria (Planktothrix perornata and Pseudanabaena sp.). The dichloromethane extract showed selective inhibition against the cyanobacterium P. perornata, with a lowest-complete-inhibition concentration (LCIC) of 10 mg/L and lowest-observed-effect concentration (LOEC) of 10 mg/L while LCIC and LOEC values were 100 mg/L when tested against S. capricornutum. This extract also showed slight meristematic cytogenic necrosis at 200 mg/L towards germinated seeds of both test plants. The compounds were not very toxic towards the channel catfish (Ictalurus punctatus) pathogenic bacteria E. ictaluri and F. columnare. Preliminary evaluation of the extract toward C. acutatum, C. fragariae and C. gloeosoprioids using TLC bioautography revealed moderate activity. However, further evaluation of the extract using a microtiter plate bioassay determined that inhibition was strongest against C. acutatum and C. fragariae, though this inhibitory activity diminished at 72 hours and was moderately less active than the commercial fungicides azoxystrobin and captan when comparing 1 - 100 mg/L levels at 48 hours.
文摘Prema 178 onion variety is widely used in production in Burkina Faso. It is greatly appreciated but susceptible to basal rot. This study aimed to evaluate the pathogenic ability of six strains of Fusarium genus identified in Burkina Faso on onion. Seeds, seedlings and bulbs were used for the test. A conidial suspension of each strain was made in tubes and adjusted to 1 × 10<sup>6</sup> conidia/ml with distilled water for the different tests. Germination test in the laboratory and greenhouse showed that all treatments with the strains of Fusarium oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, F. proliferatum and F. sp. induced failure to emerge and showed a significant difference with the control. The different strains also induced stunting rates of coleoptile growth. Fusarium oxysporum f. sp. cepae, F. acutatum, F. proliferatum, F. falciforme and F. solani were very aggressive, as they recorded above 50% damping-off rates. The test on the bulbs revealed that the strains were classified into two groups. The first consists of F. oxysporum f. sp. cepae, F. solani, F. falciforme, F. acutatum, which caused rots with respective lengths from 2.06;1.48;1.84;1.46 and 2.12 cm, thus very aggressive according to Ghanbarzadeh scale. The second is formed by F. proliferatum which recorded 0.90 cm of rot length, thus moderately aggressive. It would be appropriate to suggest a sustainable management method for these pathogens in order to improve the yield of onion production.
文摘目的为了解不同来源的人类条件病原体的特征和耐药机制,预防环境病原体和医院病原体交叉感染,对桑树中分离的克雷伯菌进行耐药性、毒力基因、分子分型特点的探究。方法从广东和广西两地采集桑树和桑树根际土壤样本,其中共分离得到12株克雷伯菌,对其采用纸片扩散法(K-B法)检测菌株耐药性表征;采用PCR技术对6类9个抗生素相关耐药基因和毒力基因进行检测;采用多位点序列分型(multilocus sequence typing,MLST)技术进行遗传分析。结果12株桑源克雷伯菌检测到bla_(SHV)、tet(D)、tet(A)和aadA14种耐药基因,其中携带氨基糖苷类相关基因aadA1的有5株(41.67%);12株桑源克雷伯菌均对氨基糖苷类抗生素红霉素和链霉素表现出耐药,对6种以上抗生素耐药的菌株有6株(50%),对7种抗生素耐药的菌株有2株(16.67%);8株(66.67%)携带脂多糖相关的wabG毒力基因;MLST分析显示12株桑源克雷伯菌划分为3大类,包括产酸克雷伯菌复合体(Klebsiella oxytoca species complex,KoSC)、肺炎克雷伯菌复合体(K.pneumoniae species complex,KpSC)以及产气克雷伯菌(K.aerogenes);可分成7个序列型(sequence typing,ST),ST260为优势序列型,有5株(41.67%)。结论12株桑源克雷伯菌对氨基糖苷类抗生素耐药情况严峻,氨基糖苷类aadA1耐药基因检出率最高;ST260是主要的序列型,菌株之间存在遗传多样性,为环境中桑树来源的克雷伯菌病原体致病机制提供理论依据。
文摘The fungal community associated with beach sand and plants located along marine coasts are an under-studied area of research despite its potential relevance to human health. In this study, we isolated and identified the cultivable mycobiota associated with sand and plants collected along the coast of Gran Canaria (Spain) using culture-dependent and -independent methods. Clinically relevant species belonging to Cryptococcus spp. and related genera such as Naganishia and Papilotrema were isolated and identified from shoreline plants. Moreover, Candida tropicalis was isolated from beach sand, and Aspergillus fumigatus and Aspergillus terreus strains were associated with both types of samples (i.e., plants and beach sand). We conclude that beach sand and shoreline plants are potential reservoirs of fungi of high clinical interest. We recommend including beach sand and plants from the environment when assessing the quality of marine coastal systems. Our results open a framework for studying the natural marine environment and its role in the epidemiology of infectious diseases in order to more accurately manage public health.
基金supported by Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(2021C02072-6)the Natural Science Foundation of Anhui Provincial Education Department(KJ2019A0574).
文摘To provide a scientific basis for controlling mulberry bacterial blight in Bazhong,Sichuan,China(BSC),this study aimed to isolate and purify pathogenic bacteria from diseased branches of mulberry trees in the region and to clarify their taxonomic status using morphological observation,physiological and biochemical detection,molecular-level identification,and the construction of a phylogenetic tree.A total of 218 bacterial strains were isolated from samples of diseased mulberry branches.Of these,7 strains were identified as pathogenic bacteria based on pathogenicity tests conducted in accordance with Koch’s postulates.Preliminary findings from the analysis of the 16S rRNA sequence indicated that the 7 pathogenic bacteria are members of Klebsiella spp.Morphological observation revealed that the pathogenic bacteria were oval-shaped and had capsules but no spores.They could secrete pectinase,cellulase,and protease and were able to utilize D-glucose,D-mannose,D-maltose,and D-Cellobiose.The 7 strains of pathogenic bacteria exhibited the highest homology with Klebsiella oxytoca.This study identifies Klebsiella oxytoca as the causative agent of mulberry bacterial blight in BSC,laying the foundation for the prevention and control of this pathogen and further investigation into its pathogenic mechanism.
