Isolation and characterization of phosphate-solubilizing bacteria from betel nut (Areca catechu) and their effects on plant growth and phosphorus mobilization in tropical soils

Phosphate-solubilizing bacteria (PSB) were isolated and characterized from the rhizosphere and bulk soils of Areca catechu plants. A long history of phosphate fertilizer use has elicited a direct effect on the incidence of soil PSB. Their abundance and ability to solubilize insoluble phosphate were significantly greater (P?<?0.0001) in soils with low available phosphorus (P) content than in other soil types. Three efficient PSB strains, namely, ASL12, ASG34, and ADH302, were identified as Acinetobacter pittii, Escherichia coli, and Enterobacter cloacae by characterizing 16S rRNA sequences and biochemical characteristics; they produced gluconic acid at concentrations of 7862.4, 4306.5, and 2663.8 mg L^?1, respectively. The highest amount of solubilized P was determined in Pikovskaya (PVK) medium for the bacterial strain ASL12. The secretion of gluconic acid was related to the available P of rhizosphere soils and P solubilization. Under shaded conditions, the application of these three strains significantly improved plant height, shoot and root dry weight, and nutrient uptake of A. catechu seedlings. A further increase in P solubilization was observed by co-inoculating the three strains and also applying tricalcium phosphate (TCP) or aluminum phosphate (AP). A significant (P?<?0.05) correlation was also observed between P-solubilization activity and A. catechu plant growth in pot experiments. Thus, the three strains can be potentially applied as inoculants in tropical and aluminum-rich soils.     

酸性土壤中解磷菌的分离及其促生效果研究

酸性土壤中磷易被固定,磷的生物有效性极低。解磷菌对土壤中难溶性磷具有重要的增溶作用。虽然已有不少解磷菌方面的研究,但是主要集中于中性和石灰性土壤中钙磷的解磷菌报道,而关于酸性土壤中高效溶解铝磷的微生物报道较少。采用培养基和土培试验,首先对酸性土壤上不同植物（胡枝子、大豆、水稻）根际土壤中的解磷菌进行了分离,然后比较了它们对不同磷源（磷酸钙和磷酸铝）的溶解能力,最后研究了它们对大豆生长和磷吸收的影响。通过使用难溶性磷源（磷酸钙和磷酸铝）的固体培养基,分离得到5株优势菌株L1、S1、S2、R1和R2,经16S rRNA序列鉴定,L1属于阮杆菌属（Nguyenibacter）,S1和S2分别属于假单胞菌属（Pseudomonas）和沙雷氏菌属（Serratia）,R1和R2分别属于伯克氏菌属（Burkholderia）和雷尔氏菌属（Ralstonia）。菌株S1、S2、R1和R2对难溶性磷酸钙有较强的溶解能力,对磷酸铝的溶解能力较弱;菌株L1对磷酸铝表现出较高的溶解能力,对难溶性磷酸钙的溶解能力弱。联合接种菌株L1+S1对大豆生长和磷吸收表现出良好的促进效果,而单独接种L1和S1效果不显著。...     

两株土壤分离菌的解磷能力及对玉米的促生作用

从植物根际的土壤样品中分离筛选出两株高效解磷细菌P_9和P_(28),分别被鉴定为粘质沙雷氏菌和产气肠杆菌.研究了不同环境条件对解磷能力的影响,结果表明,P_(28)耐 3%NaCl(w/v,下同)、28℃是两菌的最适温度、在初始pH 5.5～10.0条件下培养时能够高效溶解Ca_3(PO_4)_2.盆栽试验结果表明,单接种、双接种解磷菌处理的玉米株高、植株干重和磷含量显著高于不接菌对照;单接种P_9处理的玉米明显强于单接种P_(28)处理;将有机肥(M)和磷矿石(RP)作为载体和解磷菌一同混合施入土壤的处理,玉米苗干重,磷含量较单施解磷菌显著增加.     

根际ACC脱氨酶活性细菌的分离及其促生作用研究

从不同来源的植物根际土壤中分离出能以1-氨基环丙烷-1-羧酸(ACC)为唯一氮源生长的细菌4株,经测定均具有较高的ACC脱氨酶活性,并进一步研究了菌株对植物的促生长作用。首先进行了种子根长试验,利用菌株菌悬液处理玉米和番茄种子,结果表明,经过细菌1101、2101、4201和GXGD002处理,种子的生根长度较对照组均有明显增长,玉米种子根长相对伸长率依次为78.73%、61.72%、47.37%、47.08%;番茄种子根长相对伸长率依次为61.19%、55.84%、54.34%、51.19%。其次进行了番茄穴盘栽培试验,分别在播种后40 d和55 d收苗,测定植株的株高、茎粗、根长等生长指标,结果表明,菌株4201和GXGD002具有显著促进生长作用,其处理组植株在株高、根长、根系活力等方面较对照组均有明显增强。     

Performance of phosphate-solubilizing bacteria in soil under high phosphorus conditions

A way to bring phosphate-saturated soils back to an environmentally safe P level is by P mining through plants. Phosphate-solubilizing bacteria (PSB) could be very useful for increasing mining efficiency over time. The goal of this research was to investigate the adaptation and performance of PSB in conditions of high total P content in soil. In the first experiment, the P-solubilizing capacity of five PSB species (three Bacillus spp. and two Pseudomonas spp.) were tested under fully controlled conditions on several growth media with different forms of insoluble phosphate (FePO₄, AlPO₄, or (Ca)₃(PO₄)₂) added at different rates. The colony growth after 14 days of inoculation demonstrated that all five bacteria were able to proliferate and solubilize P on each of the tested growth media, in contradiction with the normally used technique of halo determination. In the second experiment, the same bacterial species were inoculated in pure quartz sand amended with a nutrient solution and P was added separately in an insoluble form, as Fe–P, Al–P, or Ca–P. The extractable ammonium lactate ranged from 3.2 to 6.9 and 29.0 to 40.7 mg?kg^?1 sand for the insoluble Al–P and Fe–P treatments, respectively. Pseudomonas putida and Bacillus brevis performed best as PSB at high P concentration where the P is fixed with Al or Fe. In the third experiment, P. putida and B. brevis were inoculated in an acidic sandy, P-saturated soil for 4 weeks. The inoculation of the PSB gave promising results in solubilizing P.     

Inoculation of phosphate-solubilizing bacteria Bacillus thuringiensis B1 increases available phosphorus and growth of peanut in acidic soil

Phosphate-solubilizing microorganisms play an important role in plant nutrition by enhancing phosphorus (P) availability to roots through converting the insoluble phosphates into soluble ions. We isolated phosphate-solubilizing bacteria (PSB) from acidic soil (Ultisols) in the field from the layer of 0–150 mm at a tea garden located at 28°38′26″ N and 116°24′27″ E. The capacity of bacterial isolates to solubilize mineral phosphate was tested on aluminum phosphate (AlPO₄) in liquid medium. Among these PSB, isolate B1 (identified as Bacillus thuringiensis) exhibited the maximum P-solubilizing ability and was particularly efficient at solubilizing AlPO₄ (up to 321 mg L^?1) in vitro. The isolate B1 was inoculated to an acidic soil to study its effect on phosphate solubilization and growth of peanuts (Arachis hypogeae). The Olsen-P in the tested soil increased from 14.7 to 23.4 mg kg^?1, with solubilization of 16.4 mg kg^?1 soil of Occluded-P after 14-day incubation. The inoculation by B1 significantly increased plant height (from 37.7 to 45.7 cm), number of branches (from 34.0 to 52.7 per plant), hundred-seed weight (from 42.1 to 46.9 g) and crude protein content (from 243.5 to 268.2 g kg^?1 dry weight). The phosphate-solubilizing B. thuringiensis strain B1 showed potential as a biological phosphorus fertilizer.     

溶磷菌剂对玉米幼苗生长及根际土壤细菌群落结构 和磷素形态的影响

以FD11(普瑞斯特氏菌Priestia sp.)和CH07(阿氏芽孢杆菌Bacillus aryabhattai)两种溶磷菌剂为试验材料,进行菌剂灌根盆栽试验,测定溶磷菌剂施用对玉米生长、根际土壤养分、土壤微生物特性及土壤不同形态磷含量的影响。结果表明,施用溶磷菌剂可改善根际土壤养分特征和微生物学特性,增加根际土壤的活性磷源含量,对玉米幼苗表现出良好的促生作用。与不施菌剂相比,FD11处理玉米幼苗的株高、茎粗、地上部干重分别增加31.88%、36.39%、104.00%;根际土壤碱解氮、有效磷、速效钾分别增加了21.90%、107.67%、5.77%。施用溶磷菌剂的土壤H₂O-Pi(Pi为无机磷)、NaHCO₃-P和NaOH-P含量增加,但HCl-Pi和Residual-P含量显著降低。施用溶磷菌剂改变了玉米根际土壤细菌的群落结构,在细菌属分类学水平上,不动杆菌属、假单胞菌属、海洋杆菌属、鞘氨醇单胞菌属、节杆菌属等功能细菌的相对丰度显著增加。综合以上分析,施用溶磷菌剂显著提高了土壤速效养分含量,改变了根际土壤细菌的群落结构,增加了活性磷源的...     

Isolation and characterization of mineral phosphate-solubilizing bacteria naturally colonizing a limonitic crust in the south-eastern Venezuelan region

With the aim to explore the possible role of mineral phosphate-solubilizing bacteria (PSB) in phosphorus (P) cycling in iron-rich, acidic soils, we conducted a survey of PSB naturally colonizing a limonitic crust in the south-east region of Venezuela (Bolívar State). A total of 130 heterotrophic bacterial isolates showing different degrees of mineral tri-calcium phosphate (Ca₃(PO₄)₂)-solubilizing activities were isolated from NBRIP plates. In contrast, no isolates showing iron phosphate (FePO₄)- or aluminum phosphate (AlPO₄)-solubilizing activities were detected by this experimental approach. The 10 best Ca₃(PO₄)₂-solubilizers were selected for further characterization. These isolates were shown to belong to the genera Burkholderia, Serratia, Ralstonia and Pantoea by partial sequencing analysis of their respective 16S rRNA genes. All the PSB isolates were able to mediate almost complete solubilization of Ca₃(PO₄)₂ in liquid cultures; in contrast, the PSB isolates were less effective when solubilizing FePO₄. Two groups of PSB isolates were clearly differentiated on the basis of their Ca₃(PO₄)₂ solubilization kinetics. Acidification of culture supernatants seemed to be the main mechanism for P solubilization. Indeed, gluconic acid was shown to be present in the supernatant of five isolates. Furthermore, detection of genes involved in the production of this organic acid was possible in three isolates by means of a PCR protocol.     

Isolation and identification of potassium-solubilizing bacteria from tobacco rhizospheric soil and their effect on tobacco plants

Soil potassium supplementation relies heavily on the use of chemical fertilizer, which has a considerable negative impact on the environment. Potassium-solubilizing bacteria (KSB) could serve as inoculants. They convert insoluble potassium in the soil into a form that plants can access. This is a promising strategy for the improvement of plant absorption of potassium and so reducing the use of chemical fertilizer. The objectives of this study were to isolate and characterize tobacco KSB and to evaluate the effects of inoculation with selected KSB strains on tobacco seedlings. Twenty-seven KSB strains were isolated and identified through the comparison of the 16S ribosomal DNA. Among them, 17 strains belonged to Klebsiella variicola, 2 strains belonged to Enterobacter cloacae, 2 strains belonged to Enterobacter asburiae, and the remaining 6 strains belonged to Enterobacter aerogenes, Pantoea agglomerans, Agrobacterium tumefaciens, Microbacterium foliorum, Myroides odoratimimus, and Burkholderia cepacia, respectively. All isolated KSB strains were capable of solubilizing K-feldspar powder in solid and liquid media. K. variicola occurred at the highest frequency with 18 strains. Four isolates, GL7, JM3, XF4, and XF11, were selected for a greenhouse pot experiment because of their pronounced K-solubilizing capabilities. After being treated with the four KSB strains, plant dry weight and uptake of both K and nitrogen (N) by tobacco seedlings increased significantly. These increases were higher with the combination of KSB inoculation and K-feldspar powder addition. Isolate XF11 showed the most pronounced beneficial effect on plant growth and nutrient uptake by tobacco seedlings. Combining the inoculation of KSB and the addition of K-feldspar powder could be a promising alternative to commercial K fertilizer and may help maintain the availability of soil nutrients. Further studies are necessary to determine the effects of these bacterial strains on mobilization of potassium-bearing minerals under field conditions.     

红壤溶磷菌的筛选及溶磷机制

采用以磷酸铝为磷源的蒙金娜(PVK)液体培养基研究了从红壤土中筛选出的4种溶磷菌的溶磷效果,选出其中的优势菌株B1,并对其溶磷机理做出初步探讨。结果表明,所筛选出的4株溶磷菌在液体培养条件下均有显著的溶磷效果,其中菌株B1在培养4 d后有效溶磷量最大,达到292.8 mg L-1。各处理培养液pH在培养期间均有显著下降,pH从7.0下降至3.2~4.7。高效液相色谱测定发现,各菌株培养液中有机酸的种类与含量随培养时间变化而不同,其中菌株B1主要分泌草酸和苹果酸,培养1 d后有机酸总量可达到5 mmol L-1;通过添加有机酸对磷酸铝活化的试验表明,分泌有机酸溶磷仅是菌株B1溶磷机制之一,可能还存在其他溶磷机制。菌株B1生长的适宜pH范围为5~9,最适培养温度为30℃,100 ml三角瓶的最适装液量为30~40 ml。经鉴定,菌株B1与苏云金芽孢杆菌有99.9%的相似性。     

Effect of phosphate-solubilizing bacteria and vesicular-arbuscular mycorrhizae on tomato growth and soil microbial activity

The interaction of vesicular-arbuscular mycorrhizae (VAM) and phosphate-solubilizing bacteria (PSB) on plant growth, soil microbial activities, and the production of organic acids was studied in non-sterile soil containing hydroxyapatite and glucose. Glomus etunicatum (VAM), a fungus, and Enterobacter agglomerans, a bacterium able to solubilize insoluble phosphate, were used as inocula. Three treatments and a control were used: inoculation with E. agglomerans (treatment E), inoculation with G. etunicatum (treatment G), inoculation with E. agglomerans+G. etunicatum (treatment E+G) and the control (C). Inoculation with E, G, or E+G had increased plant growth by days 35, 55, and 75 compared with the control. Microbial biomass carbon (C) and alkaline phosphatase activity in the rhizosphere generally increased with time. Alkaline phosphatase activity was higher in treatments G and E+G compared with the control at 35 and 55 days. The highest acid phosphatase activity was observed in treatment E at 35 days; however, this markedly decreased with time. A significantly higher soluble phosphorus (P) concentration was observed in treatments E and E+G on day 55 compared with C. However, there was no significant difference in soluble P concentration in the rhizosphere between treatments with time. The P concentration was greatest in all treatments on day 55. The highest oxalic acid concentration was observed in the rhizosphere of the non-sterile soil in E+G on day 35. Total N and P uptake in plants from treatments E and G were higher compared with the control. However, the highest N and P uptake was observed in treatment E+G. This study suggests a synergistic interaction between E. agglomerans and G. etunicatum. Received: 3 January 1997     

一株根际解磷菌的筛选鉴定及促生作用研究

磷在植物生长发育过程中起着重要的作用。为获得优质的解磷促生菌,以北京平谷桃园根际土壤为原料,从中筛选具有较高解磷促生能力的菌株。通过平板试验初筛可产解磷圈的菌株,再进行液态培养,采用钼锑抗比色法测定其最大的解磷能力,并探索菌株解磷能力与pH变化的关系,同时借助盆栽试验研究其促生特性。从桃树根际土共分离筛选出3株解磷菌,编号分别为JP01、JP03和PG62,初步鉴定分别为黑曲霉、杰氏假单胞菌和苍白杆菌。其中,黑曲霉JP01解磷能力优异,其溶解磷酸三钙的能力为112.52 mg/L,对卵磷脂的转化量为145.50 mg/L,最大解磷矿粉能力为95.74 mg/L,在培养过程中,该解磷菌对应的培养液pH显著下降。盆栽试验表明,黑曲霉能增加玉米幼苗株高、茎粗和地下部干重,还可使植株全磷含量增加。本研究结果可为开发解磷微生物菌剂提供优良的菌株资源。     

Soil organic carbon and phosphorus availability regulate abundance of culturable phosphate-solubilizing bacteria in paddy fields

Low availability of phosphorus(P) is a major constraint for optimal crop production, as P is mostly present in its insoluble form in soil. Therefore,phosphate-solubilizing bacteria(PSB) from paddy field soils of the Indo-Gangetic Plain, India were isolated, and their abundance was attempted to be correlated with the physicochemical characteristics of the soils. Ninety-four PSB were isolated on Pikovskaya's agar medium, and quantitative phosphate solubilization was evaluated using NBRIP medium. The isolates solubilized P up to a concentration of 1 006 μg mL~(-1) from tricalcium phosphate with the secretion of organic acids. These isolates were identified by 16 S rRNA gene sequence comparison, and they belonged to Gammaproteobacteria(56 isolates),Firmicutes(28 isolates), Actinobacteria(8 isolates), and Alphaproteobacteria(2 isolates). Phylogenetic analysis confirmed the identification by clustering the isolates in the clade of the respective reference organisms. The correlation analysis between PSB abundance and physicochemical characteristics revealed that the PSB population increased with increasing levels of soil organic carbon, insoluble P, K~+, and Mg~(2+). The promising PSB explored in this study can be further evaluated for their biofertilizer potential in the field and for their use as potent bio-inoculants.     

一株根际解磷菌的筛选鉴定及溶磷促生作用

从黄河三角洲地区盐碱化耕地的 5 种农作物根际土壤中分离筛选高效解磷菌,为开发盐碱地生物肥料提供菌种资源。结合解磷圈筛选法和钼锑抗比色法评价菌株的解磷能力;采用含不同 NaCl 浓度的 LB 培养基测定菌株的耐盐性。利用菌株的形态学特征、生理生化特性和 16S rDNA 基因序列分析方法进行鉴定;采用液体摇床培养试验测定菌株对多种难溶性磷源的溶解能力。以盐碱化土壤为供试土壤,检验菌株在盐碱土壤中的应用潜力。共分离出 27 株解磷细菌,其中菌株 B19 被鉴定为杓兰泛菌(Pantoea cypripedii),该菌在 0% ～ 4% 的 NaCl 浓度下生长良好,最高可耐受 6% 的盐浓度。B19 具有较强的解磷能力,在 Ca₃(PO₄)₂为磷源的无机磷固体培养基上30 ℃培养 3 d 解磷圈的直径(D)为 18 mm,与菌落直径(d)比达 3.17;PVK 液体培养试验表明,菌株 B19 对多种难溶性磷源都有较强的溶解能力,对 Ca₃(PO₄)₂、AlPO...     

Isolation and characterization of endophytic bacteria from wild and cultivated soybean varieties

Endophytic bacteria were isolated from surface sterilized stems, root, and nodules of wild and cultivated soybean varieties. Various phenotypic traits that are expected to be involved in the persistence and functions of the bacteria were analyzed. Most of the isolates from soybean were motile and indoleacetic acid producers, and 70 and 33% of isolates excreted cellulase and pectinase, respectively. These traits may be involved in endophytic characteristics in soybean. Some isolates were resistant to Str₁₀₀, formed capsules, and produced fluorescent pigments. Molecular characterization of selected 35 endophytic bacteria by 16S rDNA–polymerase chain reaction–restriction fragment length polymorphism showed two main clusters at 48 and 43% similarity coefficients in which most of the endophytes belonged. The genetic variation was more among endophytes isolated from Glycine max tissues than from G. soja.     

Influence of bacteria on growth and phosphorus nutrition of mycorrhizal corn

Com plants were grown in a non‐sterile soil in a greenhouse or in hydroponic culture in a growth chamber. We studied the influence of chitinolytic, pectinolytic, P‐solubilizing bacterial isolates, and a collection of bacterial strains on the development of native vesicular‐arbuscular mycorrhizal (VAM) populations, colonization of roots by the VAM fungus Glomus fasciculatum and their influence on the phosphorus (P) nutrition and growth of plants. As compared with VAM native control, the most potent stimulants for root colonization of soil‐grown plants by the VAM native population was a strain of Agrobacterium radiobacter and isolate H30. All bacteria used significantly supressed shoot fresh weight of mycorrhizal plants (‐13% up to ‐37%), with the exception of Agrobacterium. Under hydroponic conditions, the P‐solubilizing isolate F27 significantly stimulated the intensity of mycorrhiza, the number of arbuscules in roots, and increased both the P concentration and P content in corn shoots (+30% and +35%), than did the VAM fungus alone. Isolate F27 significantly increased shoot dry weight as compared with the mycorrhizal control. The other bacteria did not influence biomass production of corn.     

Enhancement of maize plant growth with inoculation of phosphate-solubilizing bacteria and biochar amendment in soil

Maize plant has an absolute requirement of nutrients (N, P, and K) for growth and development. The microbial application can facilitate in addressing limited access to chemical fertilizer concern. Moreover, biochar and phosphorus-solubilizing bacterial (PSB) community can contribute together in nutrient availability. Both have the P-supply potential to the soil, but their interaction has been tested less under semiarid climatic conditions. The purpose of the study was to evaluate the potential of biochemically tested promising PSB strains and biochar for maize plant growth and nutritional status in plant and soil. Therefore, two isolated PSB strains from maize rhizosphere were biochemically tested in vitro and identified by 16S rDNA gene analysis. The experiment was conducted in the greenhouse where the plant growth and nutrient availability to the plants were observed. In this regard, all the treatments such as PSB strain-inoculated plants, biochar-treated plants, and a combination of PSBs + biochar-treated plants were destructively sampled on day 45 (D₄₅) and day 65 (D₆₅) of sowing with four replications at each time. PSB inoculation, biochar incorporation, and their combinations have positive effects on maize plant height and nutrient concentration on D₄₅ and D₆₅. In particular, plants treated with sawdust biochar + Lysinibacillus fusiformis strain 31MZR inoculation increased N (32.8%), P (72.5%), and K (42.1%) against control on D₆₅. Besides that, only L. fusiformis strain 31MZR inoculation enhanced N (23.1%) and P (61.5%) than control which shows the significant interaction of PSB and biochar in nutrient uptake. PSB and biochar have the potential to be used as a promising amendment in improving plant growth and nutrient absorption besides the conventional approaches.     

山西矿区复垦土壤中解磷细菌的筛选及鉴定

【目的】矿区复垦土壤贫瘠、 有效磷含量低。解磷细菌能够将有机磷和难溶性无机磷转化为可溶性磷,促进植物对磷素的利用。因此筛选和鉴定具有解磷能力的菌株,可为解决矿区生态恢复使用的微生物肥料提供菌种资源。【方法】采用平板分离法初筛菌株,得到D/d1.5的菌株,然后以磷酸钙为磷源,通过液体发酵试验复筛菌株,挑选出解磷率高于巨大芽孢杆菌(Bacillus megaterium)As1.223的菌株。以磷矿粉和卵磷脂为磷源,液体发酵试验测定菌株的解磷能力及磷酸酶活性。进行菌株的生长试验以测定菌株温度适宜性、 耐盐性及耐酸碱性。通过形态学、 基因序列分析及脂肪酸组成分析综合进行菌株鉴定。 菌落形态观察用营养琼脂平板培养基培养;菌体形态即细胞形态及其大小采用扫描电镜观察;基因序列分析采用16S rDNA序列测定,基因在线比对采用EzTaxon数据库;使用美国MIDI公司的Sherolock全自动细菌鉴定系统对菌株进行脂肪酸组成分析。【结果】利用无机磷和有机磷平板培养基,从山西省矿区复垦区土壤样品中筛选出19株解磷微生物,其中D/d1.5的有7株。在以磷酸钙为磷源的液体培养试验中,4株菌的解磷率高于巨大芽孢杆菌As1.223,解磷率为7.89%～12.61%,最高的为菌株Y14。4株菌对磷矿粉的解磷率为0.81%～1.21%,最高的为菌株Y14。在以卵磷脂为磷源的液体培养试验中,4株菌的解磷率与酸性磷酸酶活性分别为1.79%～3.07%和24.3～28.4U/L,均高于巨大芽孢杆菌As1.223; 碱性磷酸酶活性为11.9～50.2U/L;菌株Y14的解磷率与磷酸酶活性均最高。4株菌均有较强的环境适应能力,以Y14的适应性最强。H22、 Y11和Y34与假单胞菌属(Pseudomonas sp.)同源性在99%以上,Y14与泛菌属(Pantoea sp.)有99.79%的同源性; H22、 Y11和Y34的细胞脂肪酸组成特征峰与假单胞菌属(Pseudomonas sp.)相一致,Y14与泛菌属(Pantoea sp.)相一致;H22、 Y11和Y34被鉴定为假单胞菌(Pseudomonas sp.),Y14为泛菌属(Pantoea sp.)。【结论】分离、 筛选到4株高效解磷菌,对于磷酸钙和卵磷脂的解磷率均高于巨大芽孢杆菌As1.223。4株菌分别隶属于假单胞菌属(Pseudomonas sp.)和泛菌属(Pantoea sp.)。菌株Y14无机磷与有机磷平板的D/d值分别为3.28与1.59,降解磷酸钙、 磷矿粉、 卵磷脂的解磷率分别为12.61%、 1.21%、 3.07%,酸性与碱性磷酸酶活性分别为28.4 U/L和50.2 U/L,均为4株菌里最高的,且环境适应能力最强,生长温度为20～60℃,能耐受pH 4～11的酸碱梯度和2%～7%的盐分梯度,Y14被鉴定为泛菌属(Pantoea sp.)。4株菌均具有良好的解磷能力及较强的环境适应能力,可望进一步研发成为微生物肥料生产菌种。综合D/d值、 解磷率、 磷酸酶活性和生长试验,本试验最终确定适合山西矿区复垦农田推广的高效解磷菌菌株为Y14。     

Isolation and characterization of lactic acid bacteria from feces of newborn baby and from dongchimi

Lactic acid bacteria were screened from feces of newborn baby and from dongchimi. Selection criteria employed included the ability of strains to withstand environmental conditions such as low pH, high bile concentration, and oxygen. The isolates were applied to the juice of various vegetables, and fermentabilities of isolates were compared. Strains F20-3, F35-3, and F35-6 showed high stability compared to the other strains at pH 3.0 and 2.3. Strains D1 and D2 showed the highest survival at pH 3.0 and survived at 1% high bile concentration. The selected strains were able to survive at low pH and relatively high bile concentration and were not affected by oxygen. The growth of isolates was >10(7) cfu/mL in natural media, and strains were not affected by the pH values of the vegetables. Therefore, isolated strains are thought to survive through the intestinal ecosystem and are considered to be suitable for application of the fermented product using various vegetables for their functionality. The isolates were identified as Lactobacillus plantarum and Lactobacillus fermentum.