Cellular Fatty Acid Composition Analysis Research Articles

Identification and Characterization of the Phosphate-Solubilizing Bacterium Pantoea sp. S32 in Reclamation Soil in Shanxi, China.

Phosphate solubilizing bacteria (PSB) can convert insoluble forms of phosphorus (P) to accessible forms. Five highly efficient PSB strains, H22, Y11, Y14, Y34, and S32, were screened and isolated from an alfalfa rhizosphere in heavy metal-contaminated reclamation area in Shanxi Province, China. Based on morphological observations, 16S rRNA sequencing, cellular fatty acid composition analysis, and the BIOLOG test, H22, Y11, and Y34 were identified as Pseudomonas sp., while Y14 and S32 were identified as Pantoea sp. Among them, S32 showed the highest P-solubilizing efficiency in culture medium containing Ca3(PO4)2, lecithin, and powered phosphate rock. The culture medium conditions to obtain the highest P-solubilization efficiency were optimized as follows: the culture temperature was 30°C; the incubation time was 5 days; the initial pH was 7.0; and glucose served as the carbon source. Furthermore, the P-solubilization efficiency of S32 in media containing CaHPO4, lecithin, phosphate rock (PR), FePO4, or AlPO4 was determined to be 18.38, 3.07, 0.16, 0.51, or 2.62%, respectively. In addition, the acid and alkali phosphatase activities of S32 were tested as 6.94 U/100 mL and 4.12 U/100 mL, respectively. The soil inoculation experiment indicated that inoculation with S32 resulted in an obvious improvement in the available P of both the experimental and reclaimed soil. The rice seedling growth experiment also suggested that the application of S32 significantly increased the plant height, biomass, root growth, and P uptake of rice in both experimental and reclaimed soil. Taken together, the isolated S32 strain showed high P-solubilization capacity for both Pi and Po, and its ameliorative effect on reclaimed soil recovery provides the theoretical basis for crop development in the reclaimed soil of mine field.

Purification and Identification of Paenibacillus sp., Isolated from Diseased Larvae of Allomyrina dichotoma (Linnaeus, 1771) (Coleoptera: Scarabaeidae) in Insect Farms

In reared populations of Allomyrina dichotoma, commercial insects, the skin of last instar larvae was changed softer with opaque white, and infested grubs eventually died. To clarify the cause of the symptom, we collected the larvae of A. dichotoma from five farms and examined their intestinal bacterial florae using pyrosequencing technique. From those results, a member of Paenibacillus was found only in the larvae showing the symptom of disease. Through PCR analysis using a Paenibacillus specific primer set, we obtained the partial 16S rRNA gene sequence and confirmed the microbe as Paenibacillus sp. For clear identification, a whole guts was extracted from each larva showing the sign of the disease and incubated at 70oC for 15 min to isolate spore forming bacteria. After then, each content of guts was cultured on MYPGPNAL agar medium(12.5 μg/ml of nalidixic acid) at 30oC. The 16S rRNA gene sequence analysis for the isolated bacteria showed that they were closely related to P. rigui(97.9% similarity), to P. chinjuensis(96.1% similarity), and to P. soli(95.3% similarity). Additional tests including API test and cellular fatty acid composition analysis were performed, but the strain couldn`t be identified at species level, suggesting it may represent novel species of the genus Paenibacillus.

Identification and Characterization of Streptococcus agalactiae Isolates using 16S rRNA Sequencing and Cellular Fatty Acid Composition Analysis

This study was undertaken to apply 16S rRNA sequence and Cellular Fatty Acid (CFA) composition analysis techniques for the identification and characterization of seven individual bacteria isolates obtained from seven infected fish samples. All samples were cultured on brain heart infusion agar. All the seven isolates were Gram positive and were identified as Streptococcus sp. The 16S rRNA sequencing method yielded about 1500 bps for each strain where upon the sequence was compared to nucleotide data in Gene Bank using BLASTN 2.2.1 sequence alignment from NCBI for the nucleotide comparison. The 16S rRNA gene sequence for all the seven samples had no sequence variation between the isolates and gave a 100% similarity to plus, plus strand with Streptococcus agalactiae strain A909 Accession number NC_007432.1 and S. agalactiae strain H36B (Accession number AAJS01000007). Also the 16S rRNA sequence showed a high (92-93%) similarity between S. agalactiae and S. equi, S. suis and S. uberis. All strains appeared to be nearly identical to each other after CFA analysis using Library Generation System (LGS) software (MIDI) and were consistent to that of S. agalactiae ATCC 12386, the CFA analysis not only confirmed the results of 16S rRNA sequence but also indicated a possibility of single source of infection. Despite their accuracy to identify the poorly described, rarely isolated, or phenotypically aberrant strains, 16S rRNA gene sequence analysis and CFA analysis lacks widespread use beyond the large and reference laboratories because of technical and cost considerations.

Paenibacillus taichungensis sp. nov., from soil in Taiwan

Among a large collection of Taiwanese soil isolates, a novel Gram-variable, rod-shaped, motile, endospore-forming bacterial strain, strain V10537(T), was subjected to a polyphasic study including 16S rRNA and gyrB gene sequence analysis, DNA-DNA hybridization experiments, cell wall peptidoglycan type, cellular fatty acid composition analysis and comparative phenotypic characterization. 16S rRNA gene sequence analysis indicated that the organism belonged to the genus Paenibacillus. Strain V10537(T) possessed meso-diaminopimelic acid as the diagnostic diamino acid of the peptidoglycan. It contained menaquinone MK-7 as the predominant isoprenoid quinone and anteiso-C(15 : 0) (53.6 %) and C(16 : 0) (19.0 %) as the major fatty acids. Phylogenetically, the most closely related species to strain V10537(T) were Paenibacillus pabuli, Paenibacillus xylanilyticus, Paenibacillus amylolyticus, Paenibacillus barcinonensis and Paenibacillus illinoisensis, with 16S rRNA gene sequence similarities of 99.5, 98.8, 98.3, 98.2 and 98.1 % to the respective type strains. The gyrB gene sequence similarities between strain V10537(T) and these strains were 76.9-85.0 %. DNA-DNA hybridization experiments showed levels of relatedness of 8.5-45.6 % between strain V10537(T) and these strains. The DNA G+C content of strain V10537(T) was 46.7 mol%. Strain V10537(T) was clearly distinguishable from other Paenibacillus species and thus represents a novel species of the genus Paenibacillus, for which the name Paenibacillus taichungensis sp. nov. is proposed. The type strain is V10537(T) (=BCRC 17757(T) =DSM 19942(T)).

A new Microbacterium species isolated from the blood of a patient with fever: Microbacterium pyrexiae sp. nov.

A Gram-positive bacterium, SMC-A8265 T, which was isolated from the blood of a patient with fever but could not be identified by a conventional microbiologic method, was finally characterized by performing phenotypic and genotypic analyses. 16S rRNA gene sequence analysis revealed that the strain SMC-A8265 T belonged to the genus Microbacterium, but it did not correspond to any of the previously described Microbacterium spp. Biochemical tests and cellular fatty acid composition analysis also confirmed that this bacterium is distinct from other Microbacterium spp. Based on the phenotypic and genotypic characteristics, we propose that the strain SMC-A8265 T should be classified as a new species, namely, Microbacterium pyrexiae sp. nov.

Bacteroides barnesiae sp. nov., Bacteroides salanitronis sp. nov. and Bacteroides gallinarum sp. nov., isolated from chicken caecum

Eight bacterial strains isolated from the caecum of chicken, BL2(T), BL66, EG3, EG6, M27, BL78(T), C35(T) and C43, were characterized by determining their phenotypic characteristics, cellular fatty acid profiles, menaquinone profiles and phylogenetic positions based on 16S rRNA gene sequence analysis. 16S rRNA gene sequence analysis showed that these isolates belonged to the genus Bacteroides. One group of five strains (BL2(T), BL66, EG3, EG6 and M27) was related most closely to Bacteroides coprocola JCM 12979(T), with approximately 93 % 16S rRNA gene sequence similarity, and to Bacteroides plebeius JCM 12973(T), with about 92 % similarity, and shared >or=99.6 % similarity with each other. Strain BL78(T) exhibited 90.5 % similarity to B. plebeius JCM 12973(T) and 89.8 % similarity to B. coprocola JCM 12979(T) and differed from the above group of five strains at >or=10 % sequence divergence. Strains C35(T) and C43 were related most closely to Bacteroides eggerthii JCM 12986(T), with 95.1 % sequence similarity, to Bacteroides stercoris JCM 9496(T), with 94.6 % similarity, and to Bacteroides uniformis JCM 5828(T), with 94.4 % similarity, and shared 100 % similarity with each other. From results of phenotypic examination, cellular fatty acid composition analysis, menaquinone composition analysis and DNA G+C contents, the group of five strains as well as strain BL78(T) were shown to differ from the type strains of B. coprocola and B. plebeius. Strain BL78(T) differed from the others based on its menaquinone composition, which included MK-11 and MK-12. Strains C35(T) and C43 could also be differentiated from the type strains of B. eggerthii, B. stercoris and B. uniformis. The group of five strains, strain BL78(T), B. coprocola JCM 12979(T) and B. plebeius JCM 12973(T) showed low levels of DNA-DNA relatedness (<35 %) with each other. High levels of DNA-DNA relatedness were obtained within the group of five strains (>75 %). Strains C35(T) and C43 exhibited a high level of DNA-DNA relatedness (>88 %) with each other, but low levels with B. eggerthii JCM 12986(T) (<40 %), B. stercoris JCM 9496(T) (<37 %) and B. uniformis JCM 5828(T) (<16 %). On the basis of these data, three novel Bacteroides species are proposed: Bacteroides barnesiae sp. nov. (type strain BL2(T)=JCM 13652(T)=DSM 18169(T)), Bacteroides salanitronis sp. nov. (type strain BL78(T)=JCM 13657(T)=DSM 18170(T)) and Bacteroides gallinarum sp. nov. (type strain C35(T)=JCM 13658(T)=DSM 18171(T)).

Early recognition of atypical Francisella tularensis strains lacking a cysteine requirement

Seven cultures referred to in our laboratories as unidentified gram-negative bacilli or Haemophilus species were identified as atypical strains of Francisella tularensis lacking a requirement for cysteine or enriched medium for growth. The use of cellular fatty acid composition analysis facilitated early recognition of this pathogen and prompt implementation of appropriate biosafety measures.