Sporosarcina jiandibaonis sp. nov., isolated from saline soil.

A Gram-stain-positive, aerobic, motile, rod-shaped bacterium, designated strain LAM9210T, was isolated from a saline soil sample collected from Lingxian County, Shandong Province, PR China. Analysis of the 16S rRNA gene sequence of the isolate revealed highest sequence similarities to the type strain of Sporosarcina pasteurii NCIMB 8841T (97.6 % sequence similarity). The genomic G+C content was 40.4 mol%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain LAM9210T and the type strain of the most closely related species S. pasteurii NCIMB 8841T were 73.6 and 20.6 %, respectively. Strain LAM9210T was found to grow at 10-40 °C (optimum, 30 °C), at pH 6.0-10.0 (optimum, pH 9.0) and with 0-6 % (w/v) NaCl (optimum, 0.5 %), respectively. The major fatty acids were anteiso-C15 : 0 and iso-C14 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and one unidentified phospholipid. Menaquinone-7 was detected as the predorminant respiratory quinone. Strain LAM9210T contained glycine, lysine, alanine and glutamic acid as the diagnostic amino acids in the cell-wall peptidoglycan. On the basis of phenotypic, phylogenetic and genotypic data, strain LAM9210T is considered to represent a novel species of the genus Sporosarcina, for which the name Sporosarcina jiandibaonis sp. nov. is proposed. The type strain is LAM9210T (=CGMCC 1.18607T=GDMCC 1.2002T=JCM 32514T).

Facultative and anaerobic consortia of haloalkaliphilic ureolytic micro-organisms capable of precipitating calcium carbonate.

AIMS: Development of biomineralization technologies has largely focused on microbially induced carbonate precipitation (MICP) via Sporosarcina pasteurii ureolysis; however, as an obligate aerobe, the general utility of this organism is limited. Here, facultative and anaerobic haloalkaliphiles capable of ureolysis were enriched, identified and then compared to S. pasteurii regarding biomineralization activities. METHODS AND RESULTS: Anaerobic and facultative enrichments for haloalkaliphilic and ureolytic micro-organisms were established from sediment slurries collected at Soap Lake (WA). Optimal pH, temperature and salinity were determined for highly ureolytic enrichments, with dominant populations identified via a combination of high-throughput SSU rRNA gene sequencing, clone libraries and Sanger sequencing of isolates. The enrichment cultures consisted primarily of Sporosarcina- and Clostridium-like organisms. Ureolysis rates and direct cell counts in the enrichment cultures were comparable to the S. pasteurii (strain ATCC 11859) type strain. CONCLUSIONS: Ureolysis rates from both facultatively and anaerobically enriched haloalkaliphiles were either not statistically significantly different to, or statistically significantly higher than, the S. pasteurii (strain ATCC 11859) rates. Work here concludes that extreme environments can harbour highly ureolytic active bacteria with potential advantages for large scale applications, such as environments devoid of oxygen. SIGNIFICANCE AND IMPACT OF THE STUDY: The bacterial consortia and isolates obtained add to the possible suite of organisms available for MICP implementation, therefore potentially improving the economics and efficiency of commercial biomineralization.

Assessing ureolytic bacteria with calcifying abilities isolated from limestone caves for biocalcification.

Biocalcification through the use of ureolytic bacteria and biochemical activities has evolved in recent decades into a fervent resourceful effective technology suitable for soil stabilization, crack repair and bioremediation. Extensive studies have been carried out on numerous ureolytic bacterial species isolated from soils and sewage samples. However, very limited attention has been given to limestone caves with natural calcite formations as a possible source for isolation of ureolytic bacteria. In this study, bacterial isolates were recovered from limestone cave samples to determine their suitability for biocalcification. Twenty-seven morphologically distinct bacterial isolates were identified by partial 16S rRNA gene sequencing and their various genetic diversity was characterized according to their phylogenetic affiliations. Based on the molecular identification, Sporosarcina was the most abundant genus among all the ureolytic isolates, while the rest belonged to Pseudogracilibacillus and Bacillus genera. Analytical analysis on urease measurement showed that urease activities for the isolates ranged from 1·130 to 21·513 mol urea hydrolysed per minute, with isolate NB33 achieving the highest value and TSB4 achieving the lowest value. The estimated CaCO3 precipitates for the isolates ranged from 4·04 to 17·26 mg ml-1 , with isolate NB30 achieving the highest value and TSB20 achieving the lowest value. The findings in this study demonstrated that the ureolytic bacteria from limestone caves are promising bio-calcifying agents. SIGNIFICANCE AND IMPACT OF THE STUDY: Ureolytic bacteria continues to play an important role as microbial tools used in geotechnical engineering for soil biocalcification. Microbial strains with the ability to produce urease enzyme and induce calcium carbonate mineral are often isolated from soil, water and sludge samples. However, screening for these essential microbes from extreme regions such as caves are rarely investigated. In this study, native bacteria which were isolated from limestone cave samples are identified and characterized. The findings suggested that these ureolytic bacterial isolates have the potential to serve as suitable alternative microbial agents for soil strengthening and stabilization.

Sporosarcina terrae sp. nov., isolated from orchard soil.

A Gram-stain-positive, motile and rod-shaped bacterium, designated strain LZ2T, was isolated from a sample of orchard soil from Laizhou city, Shandong province, PR China. On the basis of 16S rRNA gene sequence analysis, strain LZ2T was closely related to members of the genus Sporosarcina, sharing highest levels of sequence similarity with Sporosarcina pasteurii NCIMB 8841T (98.8 %), Sporosarcina soli I80T (95.9 %). The value for the DNA-DNA relatedness between strain LZ2T and Sporosarcina pasteurii NCIMB 8841T was 39.8±1.7 %. Growth occurred at 10-44 °C (optimum, 30-35 °C), pH 5.0-11.0 (optimum pH 9.0-10.0); NaCl concentrations of up to 7.0 % (w/v) were tolerated. The dominant respiratory quinone was MK-7 and the G+C content was 39.2 mol%. The major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The major polar lipids of strain LZ2T were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and an unidentified phospholipid. Based on phenotypic and chemotaxonomic characteristics, and phylogenetic data strain LZ2T represents a novel species of the genus Sporosarcina, for which the name Sporosarcina terrae sp. nov. (type strain LZ2T=KACC 18822T=MCCC 1K03174T) is proposed.

Insight into the bacterial diversity of fermentation woad dye vats as revealed by PCR-DGGE and pyrosequencing.

The bacterial diversity in fermenting dye vats with woad (Isatis tinctoria L.) prepared and maintained in a functional state for approximately 12 months was examined using a combination of culture-dependent and -independent PCR-DGGE analyses and next-generation sequencing of 16S rRNA amplicons. An extremely complex ecosystem including taxa potentially contributing to both indigo reduction and formation, as well as indigo degradation was found. PCR-DGGE analyses revealed the presence of Paenibacillus lactis, Sporosarcina koreensis, Bacillus licheniformis, and Bacillus thermoamylovorans, while Bacillus thermolactis, Bacillus pumilus and Bacillus megaterium were also identified but with sequence identities lower than 97%. Dominant operational taxonomic units (OTUs) identified by pyrosequencing included Clostridium ultunense, Tissierella spp., Alcaligenes faecalis, Erysipelothrix spp., Enterococcus spp., Virgibacillus spp. and Virgibacillus panthothenicus, while sub-dominant OTUs included clostridia, alkaliphiles, halophiles, bacilli, moderately thermophilic bacteria, lactic acid bacteria, Enterobacteriaceae, aerobes, and even photosynthetic bacteria. Based on the current knowledge of indigo-reducing bacteria, it is considered that indigo-reducing bacteria constituted only a small fraction in the unique microcosm detected in the natural indigo dye vats.

Bioremediation of Hexavalent Chromium Pollution by Sporosarcina saromensis M52 Isolated from Offshore Sediments in Xiamen, China.

OBJECTIVE: Cr(VI) removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr(VI) bioremediation from sediment samples and to optimize parameters of biodegradation. METHODS: Strains with the ability to tolerate Cr(VI) were obtained by serial dilution and spread plate methods and characterized by morphology, 16S rDNA identification, and phylogenetic analysis. Cr(VI) was determined using the 1,5-diphenylcarbazide method, and the optimum pH and temperature for degradation were studied using a multiple-factor mixed experimental design. Statistical analysis methods were used to analyze the results. RESULTS: Fifty-five strains were obtained, and one strain (Sporosarcina saromensis M52; patent application number: 201410819443.3) having the ability to tolerate 500 mg Cr(VI)/L was selected to optimize the degradation conditions. M52 was found be able to efficiently remove 50-200 mg Cr(VI)/L in 24 h, achieving the highest removal efficiency at pH 7.0-8.5 and 35 °C. Moreover, M52 could completely degrade 100 mg Cr(VI)/L at pH 8.0 and 35 °C in 24 h. The mechanism involved in the reduction of Cr(VI) was considered to be bioreduction rather than absorption. CONCLUSION: The strong degradation ability of S. saromensis M52 and its advantageous functional characteristics support the potential use of this organism for bioremediation of heavy metal pollution.

Sporosarcina siberiensis sp. nov., isolated from the East Siberian Sea.

A Gram-stain positive, non-motile, rod-shaped bacterium, designated strain 1111S-42(T), was isolated from the East Siberian Sea. The organism was found to grow at 4-30 °C, pH 7.0-8.5 and in 0-8 % (w/v) NaCl, with optimal growth occurring at 28 °C, pH 7.5 and in 1 % NaCl. Based on 16S rRNA gene sequence similarity studies, strain 1111S-42(T) was found to belong to the genus Sporosarcina and to be most closely related to Sporosarcina contaminans CCUG53915(T) (97.3 %) and Sporosarcina soli I80(T) (97.2 %). The main polar lipids were found to include diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant menaquinone was identified as MK-7. The major cellular fatty acids were identified as anteiso-C15:0 (34.4 %), iso-C15:0 (29.8 %) and anteiso-C17:0 (22.4 %). The DNA G+C content of strain 1111S-42(T) was determined to be 39 mol %. The values of DNA-DNA relatedness between the strain 1111S-42(T) and related type strains of the genus Sporosarcina were less than 30 %. Based on the phylogenetic analysis, along with extensive physiological and chemotaxonomic testing, we conclude that the bacterium represents a novel species of the genus Sporosarcina, for which the name Sporosarcina siberiensis sp. nov. is proposed. The type strain is strain 1111S-42(T) (=CGMCC 1.12516(T) = LMG 27494(T)).

[Phylogenetic analysis of bacteria of extreme ecosystems].

Phylogenetic analysis of aerobic chemoorganotrophic bacteria of the two extreme regions (Dead Sea and West Antarctic) was performed on the basis of the nucleotide sequences of the 16S rRNA gene. Thermotolerant and halotolerant spore-forming bacteria 7t1 and 7t3 of terrestrial ecosystems Dead Sea identified as Bacillus licheniformis and B. subtilis subsp. subtilis, respectively. Taking into account remote location of thermotolerant strain 6t1 from closely related strains in the cluster Staphylococcus, 6t1 strain can be regarded as Staphylococcus sp. In terrestrial ecosystems, Galindez Island (Antarctic) detected taxonomically diverse psychrotolerant bacteria. From ornithogenic soil were isolated Micrococcus luteus O-1 and Microbacterium trichothecenolyticum O-3. Strains 4r5, 5r5 and 40r5, isolated from grass and lichens, can be referred to the genus Frondihabitans. These strains are taxonomically and ecologically isolated and on the tree diagram form the joint cluster with three isolates Frondihabitans sp., isolated from the lichen Austrian Alps, and psychrotolerant associated with plants F. cladoniiphilus CafT13(T). Isolates from black lichen in the different stationary observation points on the south side of a vertical cliff identified as: Rhodococcus fascians 181n3, Sporosarcina aquimarina O-7, Staphylococcus sp. 0-10. From orange biofilm of fouling on top of the vertical cliff isolated Arthrobacter sp. 28r5g1, from the moss-- Serratia sp. 6r1g. According to the results, Frondihabitans strains most frequently encountered among chemoorganotrophic aerobic bacteria in the Antarctic phytocenoses.

Sporosarcina jeotgali sp. nov., Sporosarcina oncorhynchi sp. nov., and Sporosarcina trichiuri sp. nov., Isolated from Jeotgal, a Traditional Korean Fermented Seafood.

Three novel, Gram-stain-positive, obligate aerobic, catalase- and oxidase-positive bacterial strains, designated B2O-1T, T2O-4T, and 0.2-SM1T-5T, were isolated from jeotgal, a traditional Korean fermented seafood. Strains B2O-1T, T2O-4T, and 0.2-SM1T-5T exhibited distinct colony colors, characterized by pink, yellow, and red opaque circular colonies, respectively. Phylogenetic analysis revealed that three strains formed a paraphyletic clade within the genus Sporosarcina and shared < 99.0% similarity with Sporosarcina aquimarina KCTC 3840T and Sporosarcina saromensis KCTC 13119T in their 16S rRNA gene sequences. The three strains exhibiting Orthologous Average Nucleotide Identity values < 79.3% and digital DNA-DNA hybridization values < 23.1% within the genus Sporosarcina affirmed their distinctiveness. Strains B2O-1T, T2O-4T, and 0.2-SM1T-5T contained MK-7 as a sole respiratory menaquinone and A4α type peptidoglycan based on lysine with alanine, glutamic acid, and aspartic acid. The common polar lipids include diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Strain T2O-4T contained one unidentified phospholipid, whereas strain 0.2-SM1T-5T contained two unidentified phospholipids. Cellular fatty acid profiles, with C15:0 anteiso as the major fatty acid, supported the affiliation of the three strains to the genus Sporosarcina. Based on the polyphasic characteristics, strains B2O-1T (= KCTC 43506T = JCM 36032T), T2O-4T (= KCTC 43489T = JCM 36031T), and 0.2-SM1T-5T (= KCTC 43519T = JCM 36034T) represent three novel species within the genus Sporosarcina, named Sporosarcina jeotgali sp. nov., Sporosarcina oncorhynchi sp. nov., and Sporosarcina trichiuri sp. nov., respectively.

Chemical and microbiological characterization of atmospheric particulate matter during an intense African dust event in Southern Spain.

This study presents the results of the physicochemical characterization of particulate matter associated with an important dust event from the Sahara area that occurred in the South of Spain in 2010. The chemical composition of the samples reflected the dominance of the crustal component of sand from the Sahara desert, although the presence of Mo, Ti, and V trace elements indicated that the dust contained industrial material; probably collected in its transport from Africa. Microbial biodiversity associated with the dust was low, but dominated by Firmicutes and Proteobacteria. Some Firmicutes (belonging to the genus Bacillus and Sporosarcina) were cultured on solid and liquid medium, which suggested that the transported microbes were alive or present as spores that germinated under favorable conditions. These cultivable microbes in the form of spores were highly resistant to desiccation, heat, and UV light.

Sporosarcina newyorkensis sp. nov. from clinical specimens and raw cow's milk.

Twelve independent isolates of a gram-positive, endospore-forming rod were recovered from clinical specimens in New York State, USA, and from raw milk in Flanders, Belgium. The 16S rRNA gene sequences for all isolates were identical. The closest species with a validly published name, based on 16S rRNA gene sequence, is Sporosarcina koreensis (97.13 % similarity). DNA-DNA hybridization studies demonstrate that the new isolates belong to a species distinct from their nearest phylogenetic neighbours. The partial sequences of the 23S rRNA gene for the novel strains and their nearest neighbours also provide support for the novel species designation. Maximum-likelihood phylogenetic analysis of the 16S rRNA gene sequences confirmed that the new isolates are in the genus Sporosarcina. The predominant menaquinone is MK-7, the peptidoglycan has the type A4α L-Lys-Gly-D-Glu, and the polar lipids consist of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant fatty acids are iso-C(14 : 0), iso-C(15 : 0) and anteiso-C(15 : 0). In addition, biochemical and morphological analyses support designation of the twelve isolates as representatives of a single new species within the genus Sporosarcina, for which the name Sporosarcina newyorkensis sp. nov. (type strain 6062(T)  = DSM 23544(T)  = CCUG 59649(T)  = LMG 26022(T)) is proposed.

Calcium Carbonate Precipitation by Bacillus and Sporosarcina Strains Isolated from Concrete and Analysis of the Bacterial Community of Concrete.

Microbially induced calcium carbonate precipitation (CCP) is a long-standing but re-emerging environmental engineering process for production of self-healing concrete, bioremediation, and long-term storage of CO2. CCP-capable bacteria, two Bacillus strains (JH3 and JH7) and one Sporosarcina strain (HYO08), were isolated from two samples of concrete and characterized phylogenetically. Calcium carbonate crystals precipitated by the three strains were morphologically distinct according to field emission scanning electron microscopy. Energy dispersive X-ray spectrometry mapping confirmed biomineralization via extracellular calcium carbonate production. The three strains differed in their physiological characteristics: growth at alkali pH and high NaCl concentrations, and urease activity. Sporosarcina sp. HYO08 and Bacillus sp. JH7 were more alkali- and halotolerant, respectively. Analysis of the community from the same concrete samples using barcoded pyrosequencing revealed that the relative abundance of Bacillus and Sporosarcina species was low, which indicated low culturability of other dominant bacteria. This study suggests that calcium carbonate crystals with different properties can be produced by various CCP-capable strains, and other novel isolates await discovery.

Biosequestration of copper by bacteria isolated from an abandoned mine by using microbially induced calcite precipitation.

Abandoned mine sites are frequently polluted with high concentrations of heavy metals. In this study, 25 calcite-forming bacteria were newly isolated from the soil of an abandoned metal mine in Korea. Based on their urease activity, calcite production, and resistance to copper toxicity, four isolates were selected and further identified by 16S rRNA gene sequencing. Among the isolates, Sporosarcina soli B-22 was selected for subsequent copper biosequestration studies, using the sand impermeability test by production of calcite and extracellular polymeric substance. High removal rates (61.8%) of copper were obtained when the sand samples were analyzed using an inductively coupled plasma-optical emission spectrometer following 72 h of incubation. Scanning electron microscopy showed that the copper carbonate precipitates had a diameter of approximately 5-10 µm. X-ray diffraction further confirmed the presence of copper carbonate and calcium carbonate crystals.

Isolation and characterization of psychrotolerant endospore-forming Sporosarcina species associated with minced fish meat (surimi).

We studied the changes of resident microbiota in surimi-minced fish meat-during heat-treatment and subsequent cold-storage via the sequencing of partial 16S rRNA gene. Raw surimi made from Alaska pollock, pike conger, and white croaker was contaminated with 10(4) to 10(6)CFU/g of various non-endospore-forming bacteria. Immediately after heat-treatment, the bacterial counts were significantly reduced to less than 1CFU/g, and only endospore-forming bacteria, identified as Bacillus species were retrieved. Subsequently, the bacterial counts increased up to 10 to 10(5)CFU/g in the heated surimi after refrigerated storage at 5 °C for 2 weeks or at 10 °C for 1 week. Most of the isolates from the refrigerated surimi were identified as Sporosarcina species. The Sporosarcina isolates have an increased ability to grow at 10 °C than the isolates related to the other endospore-forming bacteria, such as Bacillus, Lysinibacillus, and Paenibacillus species. Endospores of the Sporosarcina isolates were able to germinate and proliferate in a fish-paste product model system stored at 10 °C within 8 days. In order to study the cold-adaptation mechanism of Sporosarcina species, the fatty acid composition of the isolates was analyzed. At the growth temperature of 10 °C, the proportions of unsaturated to saturated fatty acids and anteiso to iso fatty acids were higher than those at 28 °C. The alteration of the fatty acid composition suggests that Sporosarcina species adapt to cold by maintaining the fluidity of the cell membrane because unsaturated and anteiso fatty acids have lower melting points than saturated and iso fatty acids, respectively. We concluded that the endospores of Sporosarcina species are widely distributed in surimi, and that they can survive heat-treatment and proliferate during cold-storage in fish-paste products. Controlling Sporosarcina species would contribute to improving the quality of surimi product.

Biotic and abiotic effects on CO2 sequestration during microbially-induced calcium carbonate precipitation.

In this study, CO2 sequestration was investigated through the microbially-induced calcium carbonate precipitation (MICP) process with isolates obtained from a cave called 'Cave Without A Name' (Boerne, TX, USA) and the Pamukkale travertines (Denizli, Turkey). The majority of the bacterial isolates obtained from these habitats belonged to the genera Sporosarcina, Brevundimonas, Sphingobacterium and Acinetobacter. The isolates were investigated for their capability to precipitate calcium carbonate and sequester CO2. Biotic and abiotic effects of CO2 sequestration during MICP were also investigated. In the biotic effect, we observed that the rate and concentration of CO2 sequestered was dependent on the species or strains. The main abiotic factors affecting CO2 sequestration during MICP were the pH and medium components. The increase in pH led to enhanced CO2 sequestration by the growth medium. The growth medium components, on the other hand, were shown to affect both the urease activity and CO2 sequestration. Through the Plackett-Burman experimental design, the most important growth medium component involved in CO2 sequestration was determined to be urea. The optimized medium composition by the Plackett-Burman design for each isolate led to a statistically significant increase, of up to 148.9%, in CO2 uptake through calcification mechanisms.

Biomineralization processes of calcite induced by bacteria isolated from marine sediments.

Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these species, Sporosarcina sp. dominated the cultured isolates. B. lentus CP28 generated higher urease activity and facilitated more efficient precipitation of calcium carbonate at 3.24 ± 0.25 × 10(-4) mg/cell. X-ray diffraction indicated that the dominant calcium carbonate phase was calcite. Scanning electron microscopy showed that morphologies of the minerals were dominated by cubic, rhombic and polygonal plate-like crystals. The dynamic process of microbial calcium carbonate precipitation revealed that B. lentus CP28 precipitated calcite crystals through the enzymatic hydrolysis of urea, and that when ammonium ion concentrations reached 746 mM and the pH reached 9.6, that favored calcite precipitation at a higher level of 96 mg/L. The results of this research provide evidence that a variety of marine bacteria can induce calcium carbonate precipitation, and may influence the marine carbonate cycle in natural environments.

Bacterial and fungal communities in Pu'er tea samples of different ages.

Pu'er is a major kind of postfermented tea and is made with a "large leaf" variety of Camellia sinensis (C. sinensis assamica), whose distribution is limited to the mountains of southern Yunnan, China. The quality of Pu'er tea is believed to increase with storage (aging, maturing) because of postfermentation by microbes. The effect of storage period (from < 1 to 192 mo) on the bacteria and fungi in Pu'er tea was investigated by a culture-dependent and a PCR-DGGE method. The individual numbers of fungi and bacteria decreased with increasing storage time and were significantly greater in ripened tea than in raw Pu'er tea. Both methods indicated that yeast, Aspergillus spp., and Penicillium spp. were the dominant fungi in almost all the samples. However, the common bacteria detected by the culture-dependent method were species of Pseudomonas, Achromobacter, Alcaligenes, Sporosarcina, and Bacillus, whereas those detected by PCR-DGGE were species of Staphylococcus, Arthrobacter, and Streptomyces. According to ordination analysis, bacterial community structure differed between ripened and raw Pu'er tea. Bacterial diversity was positively correlated with aging time, while fungal diversity in both raw and ripened tea increased during the first 60 mo of aging and then decreased. Changes in polyphenol content were correlated with the changes in fungal diversity. These results suggest that the relationship between storage time and the quality of Pu'er tea is complex and involves changes in polyphenol content and microbial abundance and diversity.

Bioconversion of L-arabinose and other carbohydrates from plant cell walls to alpha-glucan by a soil bacterium, Sporosarcina sp. N52.

A Gram-positive bacterium, N52, that produces intracellular glucan from l-arabinose, was isolated from soil and identified as Sporosarcina sp. according to rRNA gene sequence analysis and physiological/biochemical characterizations. Glucan production by N52 increased significantly in the exponential phase of aerobic liquid culture and was maintained at the highest level during the stationary phase, reaching 37.0% of the cell dry weight. The glucan was also produced from other tested sugars originating from plant cell walls and was composed exclusively of alpha-1,4- and alpha-1,6-glucosidic linkages. When distillery waste was treated with N52 for 72 h, the total organic carbon (TOC), chemical oxygen demand and biochemical oxygen demand were reduced by 42.6%, 45.9% and 82.5%, respectively. Bacterial cells accumulated 31.9% of glucan per cell dry weight, fixing 16.0% of the TOC in the soluble fraction. Thus, this strain could provide us with a new process for waste management, including the bioconversion of organic materials to the valuable byproduct, alpha-glucan.

Biomineralization processes of calcite induced by bacteria isolated from marine sediments

Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these species, Sporosarcina sp. dominated the cultured isolates. B. lentus CP28 generated higher urease activity and facilitated more efficient precipitation of calcium carbonate at 3.24 ± 0.25 × 10−4 mg/cell. X-ray diffraction indicated that the dominant calcium carbonate phase was calcite. Scanning electron microscopy showed that morphologies of the minerals were dominated by cubic, rhombic and polygonal plate-like crystals. The dynamic process of microbial calcium carbonate precipitation revealed that B. lentus CP28 precipitated calcite crystals through the enzymatic hydrolysis of urea, and that when ammonium ion concentrations reached 746 mM and the pH reached 9.6, that favored calcite precipitation at a higher level of 96 mg/L. The results of this research provide evidence that a variety of marine bacteria can induce calcium carbonate precipitation, and may influence the marine carbonate cycle in natural environments.