Harnessing dual applications of a novel ascomycetes yeast, Starmerella cerana sp. nov., as a biocatalyst for stereoselective ketone reduction and biosurfactant production.

Introduction: New bioresources for catalytic application and fine chemical synthesis are the need of the hour. In an effort to find out new biocatalyst for oxidation-reduction reaction, leading to the synthesis of chiral intermediates, novel yeast were isolated from unique niche and employed for the synthesis of value added compounds. Methods: To determine the genetic relatedness of the isolated strain, HSB-15T, sequence analysis of the internal transcribed spacer (ITS) and D1/D2 domains of the 26S rRNA gene sequence was carried out. The distinctive features of the strain HSB-15T were also identified by phenotypic characterization. The isolated strain HSB-15T was employed for the reduction of selected naphthyl ketones to their corresponding alcohols and a biosurfactant was isolated from its culture broth. Results: The analysis of the ITS and D1/D2 domains of the 26S rRNA gene revealed that strain HSB-15T is closely related to the type strain of Starmerella vitae (CBS 15147T) with 96.3% and 97.7% sequence similarity, respectively. However, concatenated sequences of the ITS gene and D1/D2 domain showed 94.6% sequence similarity. Phenotypic characterization indicated significant differences between strain HSB-15T and its closely related species and consequently, it was identified as a novel species, leading to the proposal of the name Starmerella cerana sp. nov. The strain was able to reduce selected naphthyl ketones to their corresponding alcohols with remarkable efficiency, within a 12-hours. The strain HSB-15T also produced a surfactant in its culture broth, identified as sophorolipid upon analysis. Discussion: The study explored the potential of the novel strain, HSB-15T, as a whole-cell biocatalyst for the reduction of naphthyl ketones to their corresponding alcohols and also reports its capability to produce sophorolipid, a biosurfactant, in its culture broth. This dual functionality of HSB-15T both as biocatalyst and biosurfactant producer enhances its applicability in biotechnology and environmental science.

Effect of an Oral Health Preventive Protocol on Salivary Parameters and Gingival Health of Children with Type 1 Diabetes.

CONTEXT: Type 1 diabetic children exhibit poorer oral health than general population. However, no oral health preventive protocol exists for attending to the oral health needs of such children. AIM: To evaluate the effect of an oral health preventive protocol on salivary parameters and gingival health of children with type 1 diabetes mellitus over a period of 6 months. MATERIALS AND METHODS: Fifty diabetic children, aged 6-12 years were selected and divided into two groups. Children in group I received a comprehensive oral health preventive protocol. The parameters recorded were oral hygiene practices, salivary flow rate, pH, buffer capacity, viscosity, electrolytes, and plaque and gingival indices. These were compared at baseline, 3-, and 6-month intervals. STATISTICAL ANALYSIS: Statistical analysis was done using IBM SPSS STATISTICS (version 22.0). Tests were based on the type of data. RESULTS: The intervention group (group I) showed favorable improvements in the parameters assessed. A greater number of participants adopted the correct oral hygiene methods. Unstimulated salivary flow rate increased from 0.36 ± 0.21 to 0.82 ± 0.16 mL/minute in group I and from 0.32 ± 0.24 to 0.58 ± 0.16 mL/minute in group II after 6 months (p = 0.001). Salivary buffer capacity increased from 3.07 ± 2.64 to 10.40 ± 0.82 in group I while in group II, it improved from 3.20 ± 1.47 to 9.33 ± 1.44 (p = 0.02). Salivary viscosity decreased in group I from 1.97 ± 0.42 to 1.15 ± 0.06 and from 1.97 ± 0.35 to 1.23 ± 0.11 in group II after 6 months (p = 0.02). Gingival scores changed from 1.07 ± 0.35 to 0.20 ± 0.23 in group I and from 1.04 ± 0.28 to 0.85 ± 0.25 in group II (p = 0.001). CONCLUSION: The preventive protocol used in the present study showed a significant (p < 0.05) improvement in the parameters assessed. HOW TO CITE THIS ARTICLE: Singh V, Gauba K, Goyal A, et al. Effect of an Oral Health Preventive Protocol on Salivary Parameters and Gingival Health of Children with Type 1 Diabetes. Int J Clin Pediatr Dent 2021;14(1):109-114.

Production of Sophorolipid Biosurfactant by Insect Derived Novel Yeast Metschnikowia churdharensis f.a., sp. nov., and Its Antifungal Activity Against Plant and Human Pathogens.

Biosurfactants are potential biomolecules that have extensive utilization in cosmetics, medicines, bioremediation and processed foods. Yeast produced biosurfactants offer thermal resistance, antioxidant activity, and no risk of pathogenicity, illustrating their promising use in food formulations. The present study is aimed to assess potential of biosurfactant screened from a novel yeast and their inhibition against food spoilage fungi. A novel asexual ascomycetes yeast strain CIG-6AT producing biosurfactant, was isolated from the gut of stingless bee from Churdhar, HP, India. The phylogenetic analysis revealed that the strain CIG-6AT was closely related to Metschnikowia koreensis, showing 94.38% sequence similarity in the D1D2 region for which the name Metschnikowia churdharensis f.a., sp. nov., is proposed. The strain CIG-6AT was able to produce sophorolipid biosurfactant under optimum conditions. Sophorolipid biosurfactant from strain CIG-6AT effectively reduced the surface tension from 72.8 to 35 mN/m. Sophorolipid biosurfactant was characterized using TLC, FTIR, GC-MS and LC-MS techniques and was a mixture of both acidic and lactonic forms. Sophorolipid assessed promising activity against pathogenic fungi viz. Fusarium oxysporum (MTCC 9913), Fusarium solani (MTCC 350), and Colletotrichum gloeosporioides (MTCC 2190). The inhibitory effect of biosurfactant CIG-6AT against F. solani was studied and MIC was 49 µgm/ml, further confirmed through confocal laser scanning microscopy. We illustrated the antifungal activity of sophorolipid biosurfactant from Metschnikowia genus for the first time and suggested a novel antifungal compound against food spoilage and human fungal pathogen.

Prevalence of congenital cardiac anomalies in patients with cleft lip and palate - Its implications in surgical management.

BACKGROUND: Cleft lip and palate is one of the most common congenital craniofacial deformities seen in children. Various congenital anomalies are reported in the literature to be associated with cleft lip and palate. Cardiac anomalies are one of the most common congenital disorders associated in cleft lip and palate patientsIt includes Cyanotic and acyanotic cardiac diseases likel fallot's tetralogy, transposition of greater vessels, atresia of tricuspid, total anomalous pulmonary venous return (TAPVR), truncus arteriosus, ebstein's anomaly, hypoplastic left heart syndrome and pulmonary atresia, patent ductus arteriosus, ventricular septal defect, atrial septal defect, pulmonary stenosis, aortic stenosis and coarctation of aorta. AIM: To study the prevalence of congenital cardiac anomalies in cleft lip and palate patients. OBJECTIVES: To study different types of congenital cardiac anomalies/defects in patients with cleft lip and palate and its implications in surgical management. MATERIALS AND METHODS: This is a retrospective study carried out for a period of one year. In the present study medical records of 200 patients with cleft lip and palate were evaluated and analyzed for presence of congenital cardiac anomalies. RESULTS: Out of 200 patients of cleft lip and palate, 30 patients (15%) were associated with congenital cardiac anomalies with male to female ratio of 1:1. Associated congenital cardiac anomalies were most frequently seen in unilateral cleft palate patients (21.05%) The most common cardiac anomaly was Ventricular septal defect (36.6%).

Anterior Submandibular Approach for Transmylohyoid Endotracheal Intubation: A Reappraisal with Prospective Study in 206 Cases of Craniomaxillofacial Fractures.

Despite a paradigm shift in anesthesia and trauma airway management, the craniomaxillofacial fracture (CMF) patients continue to pose a challenge. A prospective study was planned between April 2007 and March 2015 to investigate the safety, efficacy, utility, and complications of anterior submandibular approach for transmylohyoid intubation (TMI) in CMFs using an armored endotracheal tube (ETT). Out of 1,207 maxillofacial trauma cases reported, this study recruited 206 patients (152 males and 54 females) aged between 21 and 60 years. No episode of oxygen desaturation was noted intraoperatively. Mean time to perform TMI was 6 ± 2 minutes. The mean transmylohyoid ETT withdrawal time/disconnection time from ventilator was approximately 1.5 minutes. Accidental partial extubation of ETT was noted in two patients (0.97%), and three patients (1.45%) developed abscess formations at anterior submandibular site which were managed by incision and drainage. The anterior submandibular approach for TMI was successfully used and provided stable airway in all elective CMF surgery cases, where oral or nasal intubations were not indicated/feasible and long-term ventilation support was not required. It permitted simultaneous dental occlusion-guided reduction and fixation of all the facial fractures without interference from the tube during the surgery with unhindered maintenance of the anesthesia and airway. The advantages include easy, swift, efficient, and reliable approach with a small learning curve.

Complete genome sequence and comparative genomics of the probiotic yeast Saccharomyces boulardii.

The probiotic yeast, Saccharomyces boulardii (Sb) is known to be effective against many gastrointestinal disorders and antibiotic-associated diarrhea. To understand molecular basis of probiotic-properties ascribed to Sb we determined the complete genomes of two strains of Sb i.e. Biocodex and unique28 and the draft genomes for three other Sb strains that are marketed as probiotics in India. We compared these genomes with 145 strains of S. cerevisiae (Sc) to understand genome-level similarities and differences between these yeasts. A distinctive feature of Sb from other Sc is absence of Ty elements Ty1, Ty3, Ty4 and associated LTR. However, we could identify complete Ty2 and Ty5 elements in Sb. The genes for hexose transporters HXT11 and HXT9, and asparagine-utilization are absent in all Sb strains. We find differences in repeat periods and copy numbers of repeats in flocculin genes that are likely related to the differential adhesion of Sb as compared to Sc. Core-proteome based taxonomy places Sb strains along with wine strains of Sc. We find the introgression of five genes from Z. bailii into the chromosome IV of Sb and wine strains of Sc. Intriguingly, genes involved in conferring known probiotic properties to Sb are conserved in most Sc strains.

Facile and rapid thermo-regulated biomineralization of gold by pullulan and study of its thermodynamic parameters.

A novel method for the production of gold nanoparticles (AuNPs) using pullulan as reducing and stabilizing agent has been developed. Quasi-spherical shaped AuNPs in the range of 50-100 nm were produced at three different temperature regimes 80°C, 90°C and 100°C as characterized using UV-vis spectrophotometer, TEM and DLS. Study of reaction kinetics and thermodynamic parameters indicated that the reaction between pullulan and chloroauric acid for AuNPs formation followed first order reaction kinetics and higher temperature was favorable for the synthesis of smaller sized AuNPs. FT-IR data analyses, provided an insight towards the mechanism of gold nanoparticle formation which suggested that, the free CH2OH groups of pullulan molecule were oxidized to carboxylate ions resulted in formation of AuNPs whereas the basic skeletal structure of pullulan remained unaltered. This study may open up new avenues for synthesis of tailor made biogenic AuNPs with possible application in biomedical field.

Cost effective production of pullulan from agri-industrial residues using response surface methodology.

Response surface methodology was used to develop an economically feasible process for the fermentative production of pullulan using agri-industrial residues, jaggery, de-oiled jatropha seed cake (DOJSC) and corn steep liquor (CSL), as sole media components. A second order polynomial model was obtained using central composite design to understand the effects of interactions among these substrates on pullulan biosynthesis. Results indicated that, lower concentrations of CSL and DOJSC and higher concentrations of jaggery favoured pullulan production. The optimal nutrient composition (18% jaggery, 3% DOJSC and 0.97% CSL) as suggested by the model resulted in production of 66.25 g/L pullulan with a productivity of 0.92 g/Lh. Analysis of raw material cost component for pullulan production suggested that sole utilization of agri-residues may lead to development of cost effective process for pullulan production.

Utilization of corn steep liquor for biosynthesis of pullulan, an important exopolysaccharide.

Five different agricultural wastes viz. rice bran oil cake, soya bean oil cake, cotton seed oil cake, mustard seed oil cake and corn steep liquor (CSL) were evaluated for their use as nutrient along with 15% (w/v) glucose as carbon source for biosynthesis of pullulan using Aureobasidium pullulans RBF 4A3. Among the selected agricultural wastes, CSL was found to be the best and supported production of 77.92gL(-1) pullulan under un-optimized conditions. Single point optimization technique resulted in increase in 18% pullulan (88.59gL(-1)) production. The process was successfully validated in a 7-L fermenter and a process economic analysis has suggested that use of CSL as nutrient may result in 3-fold reduction of cost of raw materials for pullulan production as compared to a process where conventional nitrogen sources were used. These observations may be helpful in development of a cost effective process for pullulan production.

A simple method to control bleeding by stationary paper clips as an alternate to raney clips during coronal incisions.

The value of coronal incisions in maxillofacial surgery has been well documented. The incision provides excellent access to the upper facial skeleton aiding in adequate access, good anatomic reduction of fractures and hidden scar. The associated bleeding with raising a bicoronal flap is a matter of concern to beginner surgeons. This often prevents the regular use of this approach. Textbooks have recommended the use of Raney clips but these are not available routinely in India and are expensive. We have utilized simple stationary paper clips, autoclaved and used for surgery. This not only provide haemostasis but also aids in holding the flap during dissection. This technique would be of great help to young surgeons and in developing countries where economics plays a major role in surgery.

Deoiledjatropha seed cake is a useful nutrient for pullulan production.

BACKGROUND: Ever increasing demand for fossil fuels is a major factor for rapid depletion of these non-renewable energy resources, which has enhanced the interest of finding out alternative sources of energy. In recent years jatropha seed oil has been used extensively for production of bio-diesel and has shown significant potential to replace petroleum fuels at least partially. De-oiled jatropha seed cake (DOJSC) which comprises of approximately 55 to 65% of the biomass is a byproduct of bio-diesel industry. DOJSC contains toxic components like phorbol esters which restricts its utilization as animal feed. Thus along with the enhancement of biodiesel production from jatropha, there is an associated problem of handling this toxic byproduct. Utilization of DOJSC as a feed stock for production of biochemicals may be an attractive solution to the problem.Pullulan is an industrially important polysaccharide with several potential applications in food, pharmaceuticals and cosmetic industries. However, the major bottleneck for commercial utilization of pullulan is its high cost. A cost effective process for pullulan production may be developed using DOJSC as sole nutrient source which will in turn also help in utilization of the byproduct of bio-diesel industry. RESULTS: In the present study, DOJSC has been used as a nutrient for production of pullulan, in place of conventional nutrients like yeast extract and peptone. Process optimization was done in shake flasks, and under optimized conditions (8% DOJSC, 15% dextrose, 28°C temperature, 200 rpm, 5% inoculum, 6.0 pH) 83.98 g/L pullulan was obtained. The process was further validated in a 5 L laboratory scale fermenter. CONCLUSION: This is the first report of using DOJSC as nutrient for production of an exopolysaccharide. Successful use of DOJSC as nutrient will help in finding significant application of this toxic byproduct of biodiesel industry. This in turn also have a significant impact on cost reduction and may lead to development of a cost effective green technology for pullulan production.

QTL analysis for grain quality traits in 2 BC2F2 populations derived from crosses between Oryza sativa cv Swarna and 2 accessions of O. nivara.

The appearance and cooking quality of rice determine its acceptability and price to a large extent. Quantitative trait loci (QTLs) for 12 grain quality traits were mapped in 2 mapping populations derived from Oryza sativa cv Swarna × O. nivara. The BC(2)F(2) population of the cross Swarna × O. nivara IRGC81848 (population 1) was evaluated during 2005 and that from Swarna × O. nivara IRGC81832 (population 2) was evaluated during 2006. Linkage maps were constructed using 100 simple sequence repeat (SSR) markers in population 1 and 75 SSR markers in population 2. In all, 21 QTLs were identified in population 1 (43% from O. nivara) and 37 in population 2 (38% QTLs from O. nivara). The location of O. nivara-derived QTLs mp1.2 for milling percent, kw6.1 for kernel width, and klac12.1 for kernel length after cooking coincided in the 2 populations and appear to be useful for Marker Assisted Selection (MAS). Four QTLs for milling percent, 1 QTL each for amylose content, water uptake, elongation ratio, 2 QTLs for kernel width, and 3 QTLs for gel consistency, each explained more than 20% phenotypic variance. Three QTL clusters for grain quality traits were close to the genes/QTLs for shattering and seed dormancy. QTLs for 4 quality traits were associated with 5 of the 7 major yield QTLs reported in the same 2 mapping populations. Useful introgression lines have been developed for several agronomic traits. It emerges that 40% O. nivara alleles were trait enhancing in both populations, and QTLs for grain quality overlapped with yield meta-QTLs and QTLs for dormancy and seed shattering.

Torulaspora indica a novel yeast species isolated from coal mine soils.

Four yeast strains (APSS 805, APSS 806, APSS 815 and AP-18) belonging to a novel Torulaspora species were isolated from coal mine soils of Singareni in Andhra Pradesh state, India. Another strain (PBA-22) was isolated from agricultural field soil from Gujarat state, India. The vegetative cells of all these strains were round, haploid and produced asci by conjugation between independent cells or mother cell and bud, with rough ascospores, suggesting their possible relation to ascomycetous yeast genus Torulaspora. Phylogenetic analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene and Internal Transcribed Spacer (ITS) regions revealed that, among the five strains, three viz. APSS 805, APSS 806 and APSS 815 have identical sequences. The other two strains (AP-18 and PBA-22) differed from the other three strains in less than 1% nucleotide substitutions in the combined D1/D2 domain and ITS sequences, indicating that all of them (five strains) may belong to the same species. These five strains were closely related to Torulaspora globosa, but showed more than 3-7% sequence divergence from T. globosa and all other species in the genus Torulaspora in the combined sequence analysis of D1/D2 domain and ITS region of rRNA gene. In addition, these strains also showed distinct microsatellite finger-printing pattern from related species and differed in several physiological responses suggesting that these strains belong to a novel species of Torulaspora. We propose to name these strains as Torulaspora indica sp. nov., and designate APSS 805(T) = MTCC 9772 (T) = CBS 12408 (T) as the type strain of this novel species. The Mycobank number of the novel species is MB 563738.

Cryptococcus rajasthanensis sp. nov., an anamorphic yeast species related to Cryptococcus laurentii, isolated from Rajasthan, India.

Two novel anamorphic yeast strains (S-15LT and 3-C1) were isolated from the inflorescences of plants collected in two different towns in Rajasthan State, India. Sequencing of the D1/D2 domains of the large-subunit (LSU) rDNA and the internal transcribed spacer (ITS) regions suggested they are strains of the same species. Phenotypic characteristics such as the absence of fermentation, the absence of sexual structures and ballistoconidia, the assimilation of myo-inositol and d-glucuronate, and positive Diazonium blue B and urease reactions indicated that these strains belong to the genus Cryptococcus. The novel strains differed from Cryptococcus laurentii in six physiological tests and differed from other related species in more than six tests. A phylogenetic analysis of the sequences of the D1/D2 domains of the LSU rDNA and the ITS regions placed these strains in the Bulleromyces clade within the order Tremellales, with C. laurentii as their closest described relative. The novel strains showed 1.6 and 7.5 % divergence in the D1/D2 domain of the LSU rDNA and ITS regions, respectively, with respect to C. laurentii. The divergence from other species was more than 3 % for the D1/D2 domain and more than 9 % for the ITS region. On the basis of the phenotypic and molecular data, strains S-15LT and 3-C1 represent a novel species within the genus Cryptococcus, for which the name Cryptococcus rajasthanensis sp. nov. is proposed. The type strain is S-15LT (=MTCC 7075T=CBS 10406T).

Actinoalloteichus spitiensis sp. nov., a novel actinobacterium isolated from a cold desert of the Indian Himalayas.

An actinobacterial strain, RMV-1378T, isolated from a cold desert of the Indian Himalayas, was subjected to polyphasic taxonomic characterization. The strain formed branching, non-fragmenting vegetative hyphae and did not produce diffusible pigments. Neither aerial mycelium nor spore formation was observed. The G+C content of the DNA was 72.0 mol%. The strain had chemotaxonomic characteristics typical of the genus Actinoalloteichus and was closely related (99.3 % 16S rRNA gene sequence similarity) to Actinoalloteichus cyanogriseus, currently the only Actinoalloteichus species with a validly published name. However, the results of DNA-DNA hybridization experiments showed 51.9 % relatedness with the type strain of A. cyanogriseus. On the basis of the above data and the physiological and biochemical distinctiveness of RMV-1378T (=MTCC 6194T=JCM 12472T=DSM 44848T), this strain should be classified as the type strain of a novel species of Actinoalloteichus, for which the name Actinoalloteichus spitiensis sp. nov. is proposed.

Aquimonas voraii gen. nov., sp. nov., a novel gammaproteobacterium isolated from a warm spring of Assam, India.

A bacterial strain designated GPTSA 20(T), which was isolated from a warm spring in Assam, India, was characterized by using a polyphasic approach. The cells were Gram-negative, aerobic rods, which could not utilize or produce acid from most of the carbohydrates tested. The predominant fatty acids were C(15:0) iso (25.04%), C(17:1) iso omega9c (19.28%), C(16:0) iso (17.73%) and C(11:0) iso 3-OH (9.34%). The G+C content was 75 mol%. From 16S rRNA gene sequence analysis (1433 nucleotides, continuous stretch), it was confirmed that strain GPTSA 20(T) belonged to the class 'Gammaproteobacteria'. The closest 16S rRNA gene sequence similarity found (98.2%) was with an uncultured bacterium clone, NB-03 (accession no. AB117707), from an autotrophic nitrifying biofilm. Among culturable bacteria, the closest sequence similarities were with Fulvimonas soli (93.0%), Silanimonas lenta (92.8%), Thermomonas hydrothermalis (92.4%), Frateuria aurantia (91.9%), Rhodanobacter lindaniclasticus (91.9%), Thermomonas haemolytica (91.9%) and Pseudoxanthomonas taiwanensis (91.8%); similarities of less than 91.8% were obtained with other members of the class 'Gammaproteobacteria'. From the biochemical, physiological, chemotaxonomic and phylogenetic analysis, it was clear that strain GPTSA 20(T) was quite different from members of known genera of the class 'Gammaproteobacteria'. Therefore, it is proposed that strain GPTSA 20(T) represents a novel species within a new genus, with the name Aquimonas voraii gen. nov., sp. nov. The type strain is GPTSA 20(T) (=MTCC 6713(T)=JCM 12896(T)).

Candida digboiensis sp. nov., a novel anamorphic yeast species from an acidic tar sludge-contaminated oilfield.

Two strains (TERI-6(T) and TERI-7) of a novel yeast species were isolated from acidic tar sludge-contaminated soil samples collected from Digboi Refinery, Assam, India. These two yeast strains were morphologically, physiologically and phylogenetically identical to each other. No sexual reproduction was observed on corn meal, malt, Gorodkowa, YM or V8 agars. Physiologically, the novel isolates were most closely related to Candida blankii, but differed in eight physiological tests. The prominent differences were the ability of the isolates to assimilate melibiose and inulin and their inability to assimilate d-glucuronate, succinate and citrate. Phylogenetic analysis using the D1/D2 variable domain showed that the closest relative of these strains is C. blankii (2.8 % divergence). Other related species are Zygoascus hellenicus and Candida bituminiphila. The isolates differed from C. blankii by 11 base substitutions in the 18S rRNA gene sequence and by 58 base substitutions in the internal transcribed spacer sequences. The physiological, biochemical and molecular data support the contention that strains TERI-6(T) and TERI-7 represent a novel species, for which the name Candida digboiensis sp. nov. is proposed. The type strain is TERI-6(T) (=MTCC 4371(T)=CBS 9800(T)=JCM 12300(T)).

Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces.

Four strains of an asexual arthroconidial yeast species were isolated from Drosophila flies in two Atlantic rain forest sites in Brazil and two strains from oak tasar silkworm larvae (Antheraea proylei) in India. Analysis of the sequences of the D1/D2 large subunit rRNA gene showed that this yeast represented a novel species of the genus Geotrichum, described as Geotrichum silvicola sp. nov. The novel species was related to the ascogenous genus Galactomyces. The closest relatives of Geotrichum silvicola were Galactomyces sp. strain NRRL Y-6418 and Galactomyces geotrichum. The type culture of Geotrichum silvicola is UFMG-354-2T (=CBS 9194T=NRRL Y-27641T).

Planococcus stackebrandtii sp. nov., isolated from a cold desert of the Himalayas, India.

The taxonomic position of a bacterium isolated from a cold desert of the Himalayas, India, was analysed by using a polyphasic approach. The isolated strain, designated K22-03T, had phenotypic characteristics that matched those of the genus Planococcus and it represents a novel species. The almost-complete 16S rRNA gene sequence (1464 bases) of the novel strain was compared with those of previously studied Planococcus type strains and confirmed that the strain belongs to the genus Planococcus. 16S rRNA gene sequence analysis indicated that strain K22-03T differs from all other species of Planococcus by at least 2.5 %. DNA-DNA hybridization showed that it had low genomic relatedness with Planomicrobium mcmeekinii (MTCC 3704T, 23 %), Planococcus psychrophilus (MTCC 3812T, 61 %), Planococcus antarcticus (MTCC 3854T, 45 %) and Planomicrobium okeanokoites (MTCC 3703T, 51 %), the four species with which it was most closely related based on 16S rRNA gene sequence analysis (97-97.5 % similarity). Therefore, strain K22-03T should be recognized as a novel species, for which the name Planococcus stackebrandtii sp. nov. is proposed. The type strain is K22-03T (=MTCC 6226T=DSM 16419T=JCM 12481T).

The D1/D2 domain of the large-subunit rDNA of the yeast species Clavispora lusitaniae is unusually polymorphic.

Ten different versions of the D1/D2 divergent domain of the large-subunit ribosomal DNA were identified among interbreeding members of the yeast species Clavispora lusitaniae. One major polymorphism, located in a 90-bp structural motif of the D2 domain, exists in two versions that differ by 32 base substitutions. Three other polymorphisms consist of a two-base substitution, a two-base deletion, and a single-base deletion, respectively. The polymorphisms are independent of one another and of the two mating types, indicating that the strains studied belong to a single, sexually active Mendelian population. Several strains were heterogeneous for one or more of the polymorphisms, and one strain was found to be automictic and capable of producing asci on its own by isogamous conjugation or by bud-parent autogamy. These observations suggest circumspection in the use of sequence divergence as the principal criterion for delimiting yeast species.