Biotransformations of steroid compounds by Chaetomium sp. KCH 6651

Biotransformations of steroid compounds: androstenedione, testosterone, progesterone, pregnenolone and DHEA using Chaetomium sp. 1 KCH 6651 strain as a biocatalyst were investigated. The microorganism proved capable of selective hydroxylation of the steroid substrates. Androstenedione was converted to 14α-hydroxyandrost-4-en-3,17-dione (in over 75% yield) and 6β-hydroxyandrost-4-en-3,17-dione (in low yield), while testosterone underwent regioselective hydroxylation at 6β position. Progesterone was transformed to a single product—6β,14α-dihydroxypregnan-4-en-3,20-dione in high yield, whereas biotransformation of DHEA resulted in the formation of 7α-hydroxy derivative, which was subsequently converted to 7α-hydroxyandrost-4-en-3,17-dione.     

Some characteristics of cytochromec-555 isolated from sulfide oxidizingXanthomonas sp. DY44

From a heterotrophic bacterium,Xanthomonas sp. DY44 which was previously reported to oxidize hydrogen sulfide (H₂S) to polysulfide, cytochromec-555 (cyt.c-555) responsible for oxidation of sulfide was purified by DEAE-Toyopearl and Sepadex G-75 column chromatography. Cyt.c-555 with a molecular weight of 12,500 showed maximum absorption at 555 nm (α-peak), 522 nm (β-peak) and 417 nm (γ-peak) for the reduced form which was prepared by addition of Na₂S₂O₄. Cyt.c-555 was also reduced by addition of sulfide (Na₂S and H₂S), and the oxidized products of sulfide by cyt.c-555 was identified as polysulfide. The reduced form of cyt.c-555 was suggested to be oxidized coupled with cyt.c oxidase which is tolerant to sulfide.     

Halorubellus salinus gen. nov., sp. nov. and Halorubellus litoreus sp. nov., novel halophilic archaea isolated from a marine solar saltern

Two extremely halophilic archaeal strains GX3(T) and GX26(T) were isolated from the Gangxi marine solar saltern near the Weihai city of Shandong Province, China. Cells from the two strains were pleomorphic and stained Gram-negative, colonies were red-pigmented. Strains GX3(T) and GX26(T) were able to grow at 25-50 °C (optimum 37 °C), at 1.4-5.1M NaCl (optimum 3.1M), at pH 5.5-9.5 (optimum pH 7.0) and neither strain required Mg(2+) for growth. Cells lyse in distilled water and the minimal NaCl concentration to prevent cell-lysis was 8% (w/v). The major polar lipids of the two strains were PA (phosphatidic acid), PG (phosphatidylglycerol), PGP-Me (phosphatidylglycerol phosphate methyl ester) and three major glycolipids (GL1, GL2 & GL3) chromatographically identical to S-TGD-1 (sulfated galactosyl mannosy glucosyl diether), S-DGD-1 (sulfated mannosyl glucosyl diether), and DGD-1 (mannosyl glucosyl diether) respectively, an unidentified lipid (GL4) was also detected in strain GX26(T). Phylogenetic analysis based on 16S rRNA gene revealed that strain GX3(T) and strain GX26(T) formed a distinct clade with the closest relative, Haladaptatus paucihalophilus (89.9-92.4% and 90.4-92.7, respectively). The rpoB' gene similarities between strains GX3(T) and GX26(T), and between the two strains and the closest relative, Halorussus rarus TBN4(T) are 96.5%, 84.3% and 83.9%, respectively. The DNA G+C contents of strain GX3(T) and strain GX26(T) are 67.3 mol% and 67.2 mol%, respectively. The DNA-DNA hybridization value between strain GX3(T) and strain GX26(T) was 44%. The phenotypic, chemotaxonomic and phylogenetic properties suggest that strain GX3(T) and strain GX26(T) represent two novel species in a new genus within the family Halobacteriaceae, Halorubellus salinus gen. nov., sp. nov. (type strain GX3(T)=CGMCC 1.10384(T)=JCM 17115(T)) and Halorubellus litoreus sp. nov. (type strain GX26(T)=CGMCC 1.10386(T)=JCM 17117(T)).     

Proposal to assign Aeromonas diversa sp. nov. as a novel species designation for Aeromonas group 501

The Aeromonas group 501, also named Aeromonas sp. HG13, is taxonomically close to A. schubertii. Results obtained in previous studies, including DNA–DNA hybridization and DNA fingerprinting, suggest that Aeromonas group 501 could constitute a different Aeromonas species. In this work we have performed a polyphasic study with the two strains comprising the Aeromonas sp. HG13 in order to propose a formal species name. They could be differentiated from A. schubertii by the indole and lysine decarboxylase tests and the utilization of l-lactate. Phenotypically, both strains were also easily separated from the other Aeromonas species. Sequence analysis of the 16S rRNA gene showed high sequence similarities (>97%) between Aeromonas group 501 and all Aeromonas species. Nevertheless, sequence divergences of cpn60, dnaJ, gyrB and rpoD genes were higher than the intraspecific threshold values established for each gene (3.5%, 3.3%, 2.3% and 2.6%, respectively), while sequence divergences between strains CDC 2478-85^T and CDC 2555-87 were low (0.6–1.1%). The DNA G+C content of the type strain was 62.2 mol%. Phenotypic and genotypic evidence strongly suggests that the Aeromonas group 501 is a novel species of the genus Aeromonas, for which the name Aeromonas diversa sp. nov. is proposed. The type strain is CDC 2478-85^T (=CECT 4254^T=ATCC 43946^T=LMG 17321^T).     

3-Phenyllactic acid production by substrate feeding and pH-control in fed-batch fermentation of Lactobacillus sp. SK007

3-Phenyllactic acid (PLA), which is produced by some strains of lactic acid bacteria (LAB), is a known antimicrobial agent with a broad spectrum. Batch and fed-batch fermentation by the strain Lactobacillus sp. SK007 for PLA production have been reported. With batch fermentation without pH-control, PLA production yield was 2.42 g L⁻¹. When fed-batch fermentation by Lactobacillus sp. SK007 was conducted in 3 L initial volume with pH-control at 6.0 and intermittent feeding, which was developed after fermentation for 12 h and every 2 h with 120 mL 100 g L⁻¹ PPA phenylpyruvic acid (PPA) and 50 mL 500 g L⁻¹ glucose each time, PLA production yield reached 17.38 g L⁻¹. The final conversion ratio of PPA to PLA was 51.1%, and the PLA production rate was 0.241 g L⁻¹ h⁻¹. This indicated that PPA was the ideal substrate for PLA fermentation production, and fed-batch fermentation with intermittent PPA feeding and pH-control was an effective approach to improve PLA production yield.     

Expandase-like activity mediated cell-free conversion of ampicillin to cephalexin by Streptomyces sp. DRS I

Cell-free extracts of Streptomyces sp. DRS I converted ampicillin to cephalexin, presumably due to the activity of the enzyme, expandase. The extract was fractionated and characterized by colorimetric and chromatographic measurements coupled with disc-agar diffusion bioassay against an ampicillin-resistant, cephalexin-sensitive E. coli strain. Though expandase could not be identified, the presence of a hitherto unreported expandase in Streptomyces sp. DRS I is suggested.     

Kytococcus aerolatus sp. nov., isolated from indoor air in a room colonized with moulds

A Gram-positive, coccoid bacterial isolate (02-St-019/1^T), forming beige pigmented colonies was obtained from an indoor air sample. Based on 16S rRNA gene sequence similarity studies it was determined that this isolate 02-St-019/1^T belonged to the genus Kytococcus, showing sequence similarties of 98.6% to Kytococcus schroeteri DSM 13884^T and 98.3% to Kytococcus sedentarius DSM 20547^T, respectively. The diagnostic diaminoacid of the peptidoglycan was lysine, cell wall sugars were ribose and xylose. The major menaquinones detected were MK-7 and MK-8. The polar lipid profile consisted of the major phospholipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine and phosphatidylinositol mannoside. Fatty acid patterns were composed of major amounts of the iso- and anteiso-branched fatty acids anteiso C_17:0, iso C_15:0 and iso C_17:0 and unsaturated fatty acids (C_17:1 ω8c, iso C_17:1 ω9c, and C_17:1 ω8c) with smaller amounts of the straight-chain fatty acids C_15:0, C_16:0 and C_17:0. The results of DNA–DNA hybridizations and physiological and biochemical tests clearly allowed a genotypic and phenotypic differentiation of strain 02-St-019/1^T from the two described Kytococcus species. On the basis of these results a novel species to be named Kytococcus aerolatus sp. nov., is proposed, with the type strain 02-St-019/1^T (=DSM 22179^T=CCM 7639^T).     

Descriptions of Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina) from Haryana,India

Two different nematodes were isolated from the bark of Albizia lebbeck trees; one from insect infested and another from noninfested, healthy tree. Based on the biological, morphological, and molecular evidences, the nematodes are described as Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina). Deladenus albizicus n. sp., isolated from insect-infested tree, multiplied on the fungus Nigrospora oryzae. Myceliophagous females of this nematode reproduced by parthenogenesis and spermathecae were indistinct. Infective females, readily produced in the cultures, are dorsally curved. Only one type of males containing small-sized sperms in their genital tracts were produced in the culture. Myceliophagous females: L = 0.75 to 1.71 mm, a = 32.3 to 50.8, b = 9.3 to 11.2, b’ = 5.2 to 7.3, c = 27.2 to 35.6, V = 91.0 to 93.3, c’ = 2.0 to 2.9, stylet = 11 to 12 µm, excretory pore in the region of median pharyngeal bulb, 43 to 47 µm anterior to hemizonid. Deladenus processus n. sp., isolated from bark of healthy A. lebbeck tree, was cultured on Alternaria alternata. Myceliophagous females reproduced by amphimixis and their spermathecae contained rounded sperms. Infective females were never produced, even in old cultures. Myceliophagous females: L = 0.76 to 0.99 mm, a = 34 to 49, b = 13.3 to 17.7, b’ = 3.8 to 5.8, c = 19.6 to 22.8, V = 92.2 to 93.5, c’ = 2.7 to 3.5, stylet = 6 to 7 µm, excretory pore in the proximity of hemizonid, tail conoid, tapering from both sides to a long pointed central process. It is proposed to classify Deladenus species in three groups: durus, siricidicola, and laricis groups based on female and spermatogonia dimorphism, mode of reproduction, and insect parasitism.     

Longidorus grandis n. sp. and L. paralongicaudatus n. sp. (Nematoda: Longidoridae), Two Parthenogenetic Species from Arkansas

Two new parthenogenetic species of Longidorus were found in Arkansas. Longidorus grandis n. sp. is characterized by its body (5.80-8.24 mm), slightly offset head, head width 20-27 µm, odontostyle 86-100 µm, guide ring 26-35 µm posterior to the anterior end, short conoid to mammiliform tail. Longidorus grandis n. sp. is similar to L. vineacola Sturhan &Weischer, 1964; L. lusitanicus Macara, 1985; L. edmundsi Hunt &Siddiqi, 1977; L. kuiperi Brinkman, Loof &Barbez, 1987; L. balticus Brzeski, Peneva &Brown, 2000; L. closelongatus Stoyanov, 1964; and L. seinhorsti Peneva, Loof &Brown, 1998. Longidorus paralongicaudatus n. sp. is characterized by its body length (2.60-5.00 µm), anteriorly flattened and offset head region 13-18 µm wide, odontostyle length 92-127 µm, guide ring 21-30 µm posterior to the anterior end, tail elongate-conical, and c'' = 1.2-2.6. Longidorus paralongicaudatus n. sp. most closely resembles L. longicaudatus Siddiqi, 1962; L. socialis Singh &Khan, 1996; L. juvenilis Dalmasso, 1969; and L. curvatus Khan, 1986.     

The haemosporidian parasites of bats with description of Sprattiella alecto gen. nov., sp. nov

Four species of Haemoproteidae were found in Pteropus alecto Temminck, 1837 in Queensland, Australia: i) Johnsprentia copemani, Landau et al., 2012; ii) Sprattiella alecto gen. nov., sp. nov., characterised by schizonts in the renal vessels; iii) Hepatocystis levinei, Landau et al., 1985, originally described from Pteropus poliocephalus Temminck, 1825 and, experimentally from Culicoides nubeculosus and found in this new host and for which features of the hepatic schizonts are reported; iv) gametocytes of Hepatocystis sp. which are illustrated but cannot be assigned to a known species. A tentative interpretation of phylogenetic characters of haemosporidians of bats is provided from the morphology of the gametocytes and localisation of the tissue stages with respect to recent data on the phylogeny of bats.     

Biotransformation of (+)-catechin into taxifolin by a two-step oxidation: primary stage of (+)-catechin metabolism by a novel (+)-catechin-degrading bacteria, Burkholderia sp. KTC-1, isolated from tropical peat

Peat contains various persistent compounds derived from plant materials. We isolated a novel (+)-catechin-degrading bacterium, Burkholderia sp. KTC-1 (KTC-1), as an example of a bacterium capable of degrading persistent aromatic compounds present in tropical peat. This bacterium was isolated by an enrichment technique and grew on (+)-catechin as the sole carbon source under acidic conditions. The reaction of a crude enzyme extract and a structural study of its products showed that (+)-catechin is biotransformed into taxifolin during the preliminary stages of its metabolism by KTC-1. HPLC analysis showed that this transformation occurs in two oxidation steps: 4-hydroxylation and dehydrogenation. Furthermore, both (+)-catechin 4-hydroxylanase and leucocyanidin 4-dehydrogenase were localized in the cytosol of KTC-1. This is the first report on biotransformation of (+)-catechin into taxifolin via leucocyanidin by an aerobic bacterium. We suggest that tropical peat could become a unique resource for microorganisms that degrade natural aromatic compounds.     

Syntrophomonas wolfei subsp. methylbutyratica subsp. nov., and assignment of Syntrophomonas wolfei subsp. saponavida to Syntrophomonas saponavida sp. nov. comb. nov

A spore-forming bacterium strain 4J5(T) was isolated from rice field mud. When co-cultured with Methanobacterium formicicum DSM 1535(T), strain 4J5(T) could syntrophically degrade saturated fatty acids with 4-8 carbon atoms, including 2-methylbutyrate. Phylogenetic analysis based on 16S rRNA gene similarity showed that strain 4J5(T) was most closely related to Syntrophomonas wolfei subsp. wolfei DSM 2245(T) (98.9% sequence similarity); however, it differed from the latter in the substrates utilized and its genetic characteristics. Therefore, a new subspecies Syntrophomonas wolfei subsp. methylbutyratica is proposed. The type strain is 4J5(T) (=CGMCC 1.5051(T)=JCM 14075(T)). Furthermore, based on 16S rRNA sequence divergence and substrate utilization, we propose the assignment of Syntrophomonas wolfei subsp. saponavida DSM 4212(T) to Syntrophomonas saponavida sp. nov. comb. nov.     

The anti-secretory and anti-ulcer activities of esomeprazole in comparison with omeprazole in the stomach of rats and rabbits

Proton pump inhibitors (PPIs) are widely used to treat hyperacid secretion and stomach ulcers. The study investigated the anti-secretory and anti-ulcer effects of esomeprazole, the S-isomer of omeprazole on dimaprit, histamine and dibutyryl adenosine 3, 5 cyclic monophosphate (dbcAMP)-evoked gastric acid secretion, acidified ethanol (AE) and indomethacin (INDO)-induced haemorrhagic lesions and on prostaglandin E₂ (PGE₂) level in the rat in vivo and rabbit in vitro preparations. The effect of omeprazole was also investigated for comparison. Dimaprit-induced acid secretion was significantly (P < 0.05) inhibited by both PPIs in a dose-dependent manner. In the isolated rabbit gastric glands, both PPIs elicited marked reductions in histamine- and dbcAMP-evoked acid secretion with similar potency. The lesions induced by either AE or INDO were significantly (P < 0.05) reduced in the presence of either esomeprazole or omeprazole compared to control values. Increasing doses of esomeprazole before AE treatment resulted in a marked degree of cytoprotection and an elevation in the concentration of bound PGE₂ in the stomach tissue homogenate. The results show that esomeprazole and omeprazole were equally effective against gastric haemorrhagic lesions induced by either AE or INDO and in inhibiting dimaprit-, dbcAMP- and histamine-induced gastric acid secretion in the rat and rabbit stomach both in vivo and in vitro. The gastro-protective effect of esomeprazole was found to be proportional to the bound PGE₂ levels in the glandular area of the stomach.     

A Simple Novel Agar Diffusion Method for Isolation of Indigenous Microalgae Chlamydomonas sp. CRP7 and Chlorella sp. CB4 from Operational Swampy Top Soil

A simple agar diffusion method is developed where pure colony of Chlamydomonas sp. CRP7 was isolated from Chlorella sp. CB4 mixtures by passing through agar migration with a light exposure of 6,000 lux for 7 h. The main concept behind it is that Chlamydomonas has flagella and the rhodopsin pigment is attracted towards light. Thus the above two microalgae species can be separated from the mixtures as eye spot serves as a navigator and flagella serves as a propeller for Chlamydomonas spp. Further the genomic DNA was isolated and purified from the above mentioned two species after the separation from the mixtures. PCR amplification was carried out for ITS1, 5.8S and ITS2 regions. The amplified products were sequenced and the sequence analysis confirmed that they belong to Chlamydomonas sp. and Chlorella sp. This is an important augmentation for isolation and separation of microalgae.     

Diplogasteroides asiaticus n. sp. is Associated with Monochamus alternatus in Japan

Diplogasteroides asiaticus n. sp. is described and illustrated, and its molecular profile and phylogenetic status within the family Diplogastridae are inferred. Morphologically, the new species is characterized by its stomatal structure, a tube-like stoma with three small, rod-like dorsal teeth and two subventral ridges; a spicule clearly ventrally bent at 1/3 from the anterior end; a gubernaculum with a rounded anterior end and sharply pointed distal end in lateral view; nine pairs of genital papillae with an arrangement of <v1, (v2, v3d), C, v4, ad, ph, (v5, v6, v7), pd>; a short tail spike in males; and a well-developed receptaculum seminis, i.e., the antiparallel blind sacs of the uteri beyond the vulva region and elongated conical tail in females. This new species is morphologically similar to D. haslacheri, but it can be distinguished by the morphology of the somewhat shorter tail in females. D. asiaticus n. sp. shares high sequence conservation with D. andrassyi as there is only one base pair difference in the nearly full-length 18S rDNA and seven base pair differences in the D2-D3 expansion segments of the 28S rDNA. Despite this sequence conservation, the species status of D. asiaticus n. sp. was confirmed using the biological species concept, as D. asiaticus n. sp. and D. andrassyi failed to generate viable F₂ progeny in hybridization tests.     

Description of Tylenchorhynchus qasimii sp. n. with a New Report of T. kegasawai from Pakistan

A new stunt nematode, from soil around the roots of coconut (Cocos nucifera L.) and rice (Oryza sativa L.) from Karachi, Pakistan, is described and illustrated as Tylenchorhynchus qasimii n. sp. This new species is characterized by having females with 3–4 head annules, anteriorly directed stylet knobs, absence of post anal extension, presence of rounded sperm filled spermatheca and conoid to bluntly rounded hemispherical tail terminus. Males are common. Also included is the record of T. kegasawai from around the roots of rice (O. sativa L.), a new report from Sindh, Pakistan.     

Autotrophic growth and inorganic sulphur compound oxidation by Sulfolobus sp. in chemostat culture

Sulfolobus strain LM was grown in tetrathionate and thiosulphate-limited continuous culture. CO₂ limitation resulted in a decrease of the steady-state biomass and an increase in the specific rate of thiosulphate oxidation so that substrate did not accumulate in the medium. The initial step in thiosulphate utilization appeared to be its conversion to tetrathionate. The affinity for tetrathionate oxidation appeared to increase with prolonged continuous culture giving an apparent K _m of about 6 M tetrathionate, a higher affinity than for thiosulphate oxidation and in the same range as values observed with acidophilic, sulphur-oxidizing eubacteria.     

Characterization of a novel fungal chitosanase Csn2 from Gongronella sp. JG

A 28kDa chitosanase designated as Csn2 was purified from the culture broth of the fungus Gongronella sp. JG through three chromatography steps: CM-Sepharose FF, Superdex 200 and SP-Sepharose FF. Its optimal reaction pH and temperature were pH 5.6 and between 55 degrees C and 60 degrees C. The half-lives of Csn2 at 50 degrees C and 55 degrees C were estimated to be 30min and 11min, respectively. The K(m) value of Csn2 in sodium acetate buffer (pH 5.6) at 55 degrees C was 8.86mg/mL. Mn(2+), Ca(2+) and Sr(2+) were activators of Csn2; ETDA was an inhibitor. Cu(2+) stimulated Csn2 at 1mM, but inhibited Csn2 activity at 10mM. Csn2 displayed strong activity on colloidal chitosan, but did not hydrolyze colloidal chitin and carboxylmethyl cellulose. Thin layer chromatography analysis showed the end products of colloidal chitosan hydrolyzed by Csn2 were chitobiose, chitotriose and chitotetraose with chitotriose as the major product. The N terminus of Csn2 was determined to be YQLPANLKKIYDSHKSGTC. Part of the genomic DNA sequence corresponding to Csn2 was cloned. Sequence alignment showed DNA sequence of Csn2 was partly identical to chitosanase genes from Metarhizium anisopliae var. acridum, Hypocrea lixii and Aspergillus fumigatus. Based on sequence similarity, Csn2 was classified as a GH-75 chitosanase.     

Respiration Responses of a Caenorhabditis sp. and Aphelenchus avenae to the Nematicide, 1,2-dibromoethane (EDB)

The respiration rate of third stage larvae of Caenorhabditis sp. exposed to 0.53 × 10⁻² M EDB was 120% greater than in untreated checks and was highest shortly after the exposure began. Similarly-treated third- and fourth-stage Aphelenchus avenae exhibited no marked respiratory response. Different responses of these animals to EDB probably reflect basic physiological differences between the nematodes.     

Biodegradation of 1,4-dioxane and transformation of related cyclic compounds by a newly isolated Mycobacterium sp. PH-06

A new bacterial strain PH-06 was isolated using enrichment culture technique from river sediment contaminated with 1,4-dioxane, and identified as belonging to the genus Mycobacterium based on 16S rRNA sequencing (Accession No. EU239889). The isolated strain effectively utilized 1,4-dioxane as a sole carbon and energy source and was able to degrade 900 mg/l 1,4-dioxane in minimal salts medium within 15 days. The key degradation products identified were 1,4-dioxane-2-ol and ethylene glycol, produced by monooxygenation. Degradation of 1,4-dioxane and concomitant formation of metabolites were demonstrated by GC/MS analysis using deuterium labeled 1,4-dioxane (1,4-dioxane-d8). In addition to 1,4-dioxane, this bacterium could also transform structural analogues such as 1,3-dioxane, cyclohexane and tetrahydrofuran when pre-grown with 1,4-dioxane as the sole growth substrate. Our results suggest that PH-06 can maintain sustained growth on 1,4-dioxane without any other carbon sources.