Spring In Taiwan Research Articles

Current Status and Conservation of Springs in Taiwan: Water Quality Assessment and Species Diversity of Aquatic Animals

Even though spring ecosystems are ecologically unique and socio-culturally important worldwide, they hardly attract research attention. The aims of this study were to evaluate the environmental status of water quality, and to inventory the species diversity of aquatic animals in 65 springs in Taiwan from 2012 to 2017, of which seven springs were unable to be sampled due the fact that they were dried or sealed up. The environmental status of 58 springs with complete water quality data was assessed by the River Pollution Index (RPI). Based on the RPI, the water quality of these 58 sampled springs was mainly non-/mildly polluted (26 springs, 44.8%) and lightly polluted (23 spring, 39.6%), and nine (15.5%) springs were moderately polluted. However, when applied to springs, the RPI may intensify the pollution rankings because dissolved oxygen is an assessing factor, and hypoxia may naturally be observed in the springs. To avoid this concern, we suggest choosing the concentration of coliform instead of dissolved oxygen content in the RPI when it is applied to springs. During the 6 years of the study period, we collected 48 fish species in 44 springs, 24 gastropoda and bivalve species in 46 springs, 16 shrimp species in 34 springs, and 14 crab species in 18 springs. Within the species collected, 31 fish, 20 gastropoda and bivalves, 12 shrimps, and 14 crabs are native species of Taiwan. They totaled 27.2 to 35% of the known aquatic native species of the island. Thus, springs in Taiwan may be considered to be a conservation hotspot of aquatic animals. Other than native species, exotic aquatic animals also represent threats, as seventeen fishes (35.4%), four gastropoda and bivalves (16.6%), and two shrimps (12.5%) were found in the springs of Taiwan. The springs in Taiwan show diverse and vital ecosystem services, such as delivering social, cultural, and economic value, conserving native and endangered freshwater animals, developing new academic theories, and supplying habitat refugees from climate change. Unfortunately, springs in Taiwan currently are also threatened by multiple anthropogenic disturbances, such as the overconsumption of groundwater by land development and urbanization, deterioration of water quality by agricultural, domestic, and industrial pollution, and inappropriate tourism and management tactics. To restore and sustain the springs in Taiwan, effective strategies and practical measures are urgently required to minimize human-caused threats and revitalize social awareness of springs.

Comparative analysis reveals distinctive genomic features of Taiwan hot-spring cyanobacterium Thermosynechococcus sp. TA-1.

Thermosynechococcus is a genus of thermophilic unicellular cyanobacteria that dominates microbial mats in Asian non-acidic hot springs. These cyanobacteria are the major primary producers in their ecological niches and are promising sources of thermostable enzymes for biotechnology applications. To improve our understanding of these organisms, we conducted whole-genome sequencing of a novel strain for comparative analysis with other representatives in the same genus. This newly characterized strain, Thermosynechococcus sp. TA-1, was isolated from the Taian hot springs in Taiwan. Analyses based on average nucleotide identity (ANI) and genome-scale phylogeny suggested that TA-1 and another Taiwanese strain CL-1 belong to a novel species-level taxon. Two metagenome-assembled genomes (MAGs) originated from India represent the sister group, and Thermosynechococcus elongatus PKUAC-SCTE542 from China is the next closest lineage. All cultivated strains and MAGs from Japan form a separate monophyletic clade and could be classified into two species-level taxa. Intriguingly, although TA-1 and CL-1 share 97.0% ANI, the genome alignment identified at least 16 synteny breakpoints that are mostly associated with transposase genes, which illustrates the dynamic nature of their chromosomal evolution. Gene content comparisons identified multiple features distinct at species- or strain-level among these Thermosynechococcus representatives. Examples include genes involved in bicarbonate transportation, nitric oxide protection, urea utilization, kanamycin resistance, restriction-modification system, and chemotaxis. Moreover, we observed the insertion of type II inteins in multiple genes of the two Taiwanese strains and inferred putative horizontal transfer of an asparagine synthase gene (asnB) associated with exopolysaccharides gene cluster. Taken together, while previous work suggested that strains in this genus share a highly conserved genomic core and no clear genetic differentiation could be linked to environmental factors, we found that the overall pattern of gene content divergence is largely congruent with core genome phylogeny. However, it is difficult to distinguish between the roles of phylogenetic relatedness and geographic proximity in shaping the genetic differentiation. In conclusion, knowledge of the genomic differentiation among these strains provides valuable resources for future functional characterization.

Nitrogen and 17β-Estradiol level regulate Thermosynechococcus sp. CL-1 carbon dioxide fixation, monosaccharide production, and estrogen degradation

Thermosynechococcus sp. CL-1 (TCL-1), a thermophilic cyanobacterium from a hot spring in Taiwan, has been known of its efficiency in CO2 fixation, byproducts production (pigments, macromolecules). This study observed the performance of TCL-1 in CO2 fixation, estrogen degradation, and monosaccharide production under various levels of Dissolved Inorganic Nitrogen (DIN) and 17β-estradiol (E2) as nitrogen supply and estrogen addition. Under nitrogen starvation, TCL-1 performed similar results on CO2 fixation rate and biomass production but enhanced the monosaccharide production compared to the cases of high nitrogen supply. The highest CO2 fixation rate and glucose productivity reached to 151.8 ± 6.6 and 38.1 ± 0.9 mg/L/h, under DIN level of 0.58 mM and 0.5 mg/L E2. Adding E2 in the system did not inhibit the performance of TCL-1. During the cultivation, TCL-1 converted E2 into E1 and the biodegradation was the main path for estrogen degradation. Total E2 degradation reached to 69.4 ± 2.0%.

Improvement of Thermosynechococcus sp. CL-1 performance on biomass productivity and CO2 fixation via growth factors arrangement

The enormous attraction on CO2 biofixation using photosynthetic microorganisms such as cyanobacteria has been risen due to its promising efficiency and valuable by-products production. In this study, an isolated cyanobacterium from hot spring in Taiwan, Thermosynechococcus sp. CL-1 (TCL-1) was evaluated for its growth factors arrangement effect on the biomass productivity and CO2 biofixation. The initial biomass concentration, and nutrient supply level variation influenced TCL-1 biomass productivity and CO2 biofixation rate while the adjusted and controlled pH value gave an insignificant difference on its performance. The initial biomass concentration of 3 g L−1 gave the best result on biomass productivity and CO2 fixation which reached 143.4 mg L−1 h−1 and 224 mg L−1 h−1 respectively. Regarding to the result of this study, controlled pH value by the CO2 supply inside the reactor, produced an insignificant difference in TCL-1 performance compared to those with the uncontrolled pH value. The variation of nutrient supply level was achieved by the variation of macronutrient and micronutrient supply inside the medium. The G-solution contains metals and other micronutrient elements which are necessary for the growth of TCL-1. The combination between 5–folds MF medium as the macronutrient, and 3-folds G-solution as the micronutrient supply, present the best TCL-1 performance on biomass productivity and CO2 fixation rate.

Sphingobium algorifonticola sp. nov., isolated from a cold spring.

Strain TLA-22T, isolated from a cold spring in Taiwan, was characterized using a polyphasic taxonomy approach. Cells were Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, motile by means of a single polar flagellum, rod-shaped and formed bright yellow colonies. Optimal growth occurred at 20-25 °C, pH 6-6.5, and in the presence of 0.5 % NaCl. The major fatty acids of TLA-22T were C18 : 1 ω7 c and C17 : 1ω6c. The predominant hydroxy fatty acids were C15 : 0 2-OH and C14 : 0 2-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine, sphingoglycolipid, an unidentified aminophospholipid, an unidentified phospholipid and three unidentified lipids. TLA-22T contained spermidine as the major polyamine and putrescine as the minor component. The only isoprenoid quinone was Q-10. The genomic DNA G+C content of TLA-22T was 63.2 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that TLA-22T was a mem,ber of a phylogenetic lineage including members of the genus Sphingobium. TLA-22T was most closely related to Sphingobium aromaticiconvertens RW16T, with a 97.4 % 16S rRNA gene sequence similarity. TLA-22T showed 74.8-75.7 % average nucleotide identity and 20.1-22.0 % digital DNA-DNA hybridization identity with the strains of other species of the genus Sphingobium. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TLA-22T should be classified as representing a novel species of the genus Sphingobium, for which the name Sphingobium algorifonticola sp. nov. is proposed. The type strain is TLA-22T (=BCRC 81097T =LMG 30309T=KCTC 62189T).

Using a 1D numerical temperature recovery model to estimate in-situ thermal diffusivity by an up-welling heat source in an artesian well

The determination of thermal diffusivity is a pre-requisite for geothermal site characterization and utilization. The temperature recovery (TR) method is a popular method for determining in-situ thermal conductivity together with the thermal response test and thermal conductivity probe methods. To determine in-situ thermal properties of the subsurface following a thermal disturbance produced by drilling processes or a heating cable within a borehole, the TR method is used to record decaying temperatures during the recovery period. However, to date, no studies exist to determine thermal diffusivity using up-welling water within a well. In this study, we introduce a 1D numerical method for estimating in-situ thermal diffusivity of the subsurface using up-welling thermal water as a heat source within an artesian well. Our numerical model includes parameters for the position of a sensor within a borehole, as well as for the thermal properties of a well casing and an annulus. Two data sets from the scientific literature were used to verify our model. Field data from the Jiashi Hot Spring in Taiwan were also used to demonstrate model suitability. Our model’s value for thermal conductivity is consistent with the range of values for saturated sand within the scientific literature. Accuracies for thermal diffusivity estimations under short disturbance/recovery period were also evaluated. The results suggest that in-situ thermal diffusivity can be accurate determined, with an error less than 10%, using a short testing period with pumping time as low as four hours and a recovery of 24 h.

Paracoccus fontiphilus sp. nov., isolated from a freshwater spring.

Strain MVW-1T, isolated from a freshwater spring in Taiwan, was characterized by using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain MVW-1T belongs to the genus Paracoccus and has the highest levels of sequence similarity to Paracoccus caeni MJ17T (97.6 %), Paracoccus sediminis CMB17T (97.4 %), Paracoccus angustae E6T (97.3 %) and Paracoccus acridae SCU-M53T (97.1 %). Cells were Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, non-motile, rod-shaped and formed light orange-coloured colonies. Optimal growth occurred at 20-25 °C, pH 6-7, and in the presence of 0-3 % NaCl. The major fatty acid of strain MVW-1T was C18 : 1ω7c. The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol, an unidentified glycolipid, an unidentified aminolipid and three unidentified phospholipids. The predominant polyamines were spermidine, putrescine and cadaverine. The only isoprenoid quinone was Q-10. The genomic DNA G+C content of strain MVW-1T was 63.4 mol%. Strain MVW-1T exhibited less than 35 % DNA-DNA relatedness to P. caeni MJ17T, P. angustae E6T, P. sediminis CMB17T and P. acridae SCU-M53T. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain MVW-1T should be classified in a novel species of the genus Paracoccus, for which the name Paracoccus fontiphilus sp. nov. is proposed. The type strain is MVW-1T (=BCRC 80974T=LMG 29554T=KCTC 52239T).

Hymenobacter gummosus sp. nov., isolated from a spring.

Strain ANT-18T, isolated from a water sample taken from the Longtoushan Spring in Taiwan, was characterized using a polyphasic taxonomic approach. Cells of strain ANT-18T were Gram-stain-negative, aerobic, motile by gliding rods that were surrounded by a thick capsule and it formed pink colonies. Growth occurred at 20-37 °C (optimum, 25 °C), at pH 6-8 (optimum, pH 7) and with 0-1 % NaCl (w/; optimum, 0 %). Phylogenetic analyses, based on 16S rRNA gene sequences, showed that strain ANT-18T belongs to the genus Hymenobacter and showed the highest levels of sequence similarity to Hymenobacter ocellatus Myx 2105T (97.8 %) and Hymenobacter paludis KBP-30T (97.7 %). Strain ANT-18T contained iso-C15 : 0, anteiso-C15 : 0, C18 : 0 and summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B) as the predominant fatty acids. The major isoprenoid quinone was MK-7. The polar lipid profile consisted of phosphatidylethanolamine, one uncharacterized aminolipid, two uncharacterized aminophospholipids, two uncharacterized glycolipids and seven uncharacterized lipids. The major polyamine was homospermidine. The genomic DNA G+C content of strain ANT-18T was 63.6 mol%. The DNA-DNA relatedness values of strain ANT-18T with respect to H. ocellatus Myx 2105T and H. paludis KBP-30T were less than 35 %. On the basis of the phylogenetic inference and phenotypic data, strain ANT-18T is recognized to be a representative of a novel species within the genus Hymenobacter. The name Hymenobacter gummosus sp. nov. is proposed, with strain ANT-18T (=BCRC 80966T=LMG 29477T=KCTC 52166T) as the type strain.

Flavobacterium dispersum sp. nov., isolated from a freshwater spring.

A novel bacterial strain MVW-23T was isolated from a freshwater spring in Taiwan. The strain was Gram-staining-negative, strictly aerobic, motile by gliding, rod-shaped and formed translucent yellow colonies. Optimal growth occurred at 20-30 °C, pH 7.0, and in the presence of 0.5-1 % NaCl. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain MVW-23T belonged to the genus Flavobacterium and showed the highest levels of sequence similarity with respect to Flavobacterium denitrificans ED5T (97.3 %), Flavobacterium kyungheense THG-107T (97.2 %) and Flavobacterium defluvii EMB117T (97.0 %). Strain MVW-23T contained iso-C15 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and iso-C17 : 0 3-OH as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, three uncharacterized aminophospholipids and one uncharacterized phospholipid. The major polyamine was homospermidine. The major isoprenoid quinone was MK-6. The DNA G+C content of the genomic DNA was 39.9 mol%. The DNA-DNA hybridization value for strain MVW-23T with F. denitrificans DSM 15936T, F. kyungheense LMG 26575T and F. defluvii DSM 17963T was less than 35 %. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain MVW-23T should be classified as a novel species of the genus Flavobacterium, for which the name Flavobacterium dispersum sp. nov. is presented. The type strain is MVW-23T (=BCRC 80978T=LMG 29558T=KCTC 52234T).

Cellvibrio fontiphilus sp. nov., isolated from a spring.

A bacterial strain, designated MVW-40T, was isolated from Maolin Spring in Taiwan and characterized using a polyphasic taxonomy approach. Cells of strain MVW-40T were Gram-negative, strictly aerobic, motile by a single polar flagellum and bright yellow-pigmented rods with pointed ends. Growth occurred at 15-40 °C (optimum, 20-30 °C), at pH 6-9 (optimum, pH 6) and with 0-2 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain MVW-40T belonged to the genus Cellvibrio and showed the highest levels of sequence similarity with respect to Cellvibrio mixtussubsp. mixtus ACM 2601T (98.1 %) and Cellvibrio fibrivorans R-4079T (97.2 %). Strain MVW-40T contained summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, two uncharacterized aminophospholipids, two uncharacterized phospholipids and an uncharacterized lipid. The DNA G+C content of the genomic DNA was 52.8 mol%. The DNA-DNA hybridization value for strain MVW-40T with C. mixtussubsp. mixtus ACM 2601T and C. fibrivorans R-4079T was less than 45 %. On the basis of the phylogenetic inference and phenotypic data, strain MVW-40T should be classified as a novel species, for which the name Cellvibrio fontiphilus sp. nov. is proposed. The type strain is MVW-40T (=BCRC 80977T=LMG 29557T=KCTC 52237T).

Novosphingobium fontis sp. nov., isolated from a spring

A bacterial strain designated STM-14T was isolated from a spring in Taiwan and characterized using a polyphasic taxonomic approach. Strain STM-14T was a Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, non-motile, rod-shaped bacterium and formed cream-coloured colonies. Strain STM-14T grew at 15-37 °C (optimum, 30 °C), at pH 5.0-9.0 (optimum, pH 6.0) and with 0-0.5 % (w/v) NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain STM-14T belonged to the genus Novosphingobium and showed the highest levels of sequence similarity to Novosphingobium naphthae D39T (98.5 %) and Novosphingobium mathurense SM117T (97.6 %). The major fatty acids (>10 %) of strain STM-14T were C17 : 1ω6c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C18 : 1ω7c, C15 : 0 2-OH and C17 : 1ω8c. The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidyldimethylethanolamine, sphingoglycolipid, phosphatidylcholine and several uncharacterized lipids. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 66.6 mol%. The DNA-DNA hybridization value for strain STM-14T with N. naphthae JCM 31158T and N. mathurense DSM 23374T was less than 49 %. Differential phenotypic properties, together with the phylogenetic inference, demonstrate that strain STM-14T should be classified as representing a novel species of the genus Novosphingobium, for which the name Novosphingobium fontis sp. nov. is proposed. The type strain is STM-14T (=BCRC 80924T=LMG 29290T=KCTC 42983T).

Flectobacillus pallidus sp. nov., isolated from a freshwater spring

A novel bacterial strain, MVW-6T, was isolated from a freshwater spring in Taiwan and characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain MVW-6T belonged to the genus Flectobacillus and showed the highest levels of sequence similarity to Flectobacillus lacus CL-GP79T (98.2 % 16S rRNA gene sequence similarity) and Flectobacillus fontis MIB-4T (97.4 %). Cells of strain MVW-6T were Gram-stain-negative, aerobic, non-motile rods that were covered by large capsules and formed light pink colonies. Growth occurred at 15-37 °C (optimum 15-25 °C), at pH 5-9 (optimum pH 7) and with 0-0.5 % (w/v) NaCl (optimum 0 %). Strain MVW-6T contained iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 1ω5c and C16 : 0 as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, five unidentified aminophospholipids, one unidentified glycolipid, one unidentified phospholipid, one unidentified aminolipid and two unidentified lipids. The major isoprenoid quinone was MK-7. The G+C content of the genomic DNA was 39.5 mol%. DNA-DNA hybridization values for strain MVW-6T with Flectobacillus lacus CL-GP79T and Flectobacillus fontis MIB-4T were less than 50 %. On the basis of the phylogenetic inference and phenotypic data, strain MVW-6T a novel species of the genus Flectobacillus, for which the name Flectobacillus pallidus sp. nov. is proposed. The type strain is MVW-6T (=BCRC 80975T=LMG 29555T=KCTC 33800T).

Draft Genome Sequence of Chromobacterium aquaticum CC-SEYA-1, a Nonpigmented Member of the Genus Chromobacterium.

ABSTRACTChromobacterium aquaticum CC-SEYA-1T, isolated from a spring in Taiwan, shares many characteristics with other members of the genus but also contains auxin biosynthesis genes and does not produce the pigment violacein. Chromobacterium sp. 49, isolated from Brazil, is identified here as C. aquaticum, indicating that this is a cosmopolitan species.

Flectobacillus fontis sp. nov., isolated from a freshwater spring.

A bacterial strain, designated MIB-4T, was isolated from a freshwater spring in Taiwan and characterized using a polyphasic taxonomy approach. Cells of strain MIB-4T were Gram-staining-negative, aerobic, non-motile rods that formed pale pink colonies. Growth occurred at 15-30 °C (optimum, 25 °C), at pH 7-8 (optimum, pH 7) and with 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain MIB-4T belonged to the genus Flectobacillus and was most closely related to Flectobacillus lacus CL-GP79T with sequence similarity of 98.7 %. Strain MIB-4T contained C16 : 1ω5c, iso-C15 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the predominant fatty acids. The major isoprenoid quinone was MK-7. The polar lipid profile consisted of phosphatidylethanolamine, six unidentified aminophospholipids, one unidentified glycolipid, one unidentified phospholipid and three unidentified lipids. The DNA G+C content of the genomic DNA was 37.6 mol%. The DNA-DNA hybridization value for strain MIB-4T with F. lacus CL-GP79T was less than 32 %. On the basis of the phylogenetic inference and phenotypic data, strain MIB-4T should be classified as a representative of a novel species, for which the name Flectobacillus fontis sp. nov. is proposed. The type strain is MIB-4T (=BCRC 80926T=LMG 29292T=KCTC 33763T).

Novosphingobium bradum sp. nov., isolated from a spring.

A bacterial strain designated STM-24T was isolated from a spring in Taiwan and characterized using the polyphasic taxonomic approach. Cells of strain STM-24T were Gram-staining- negative, aerobic, poly-β-hydroxybutyrate accumulating, non-motile, rod shaped and forming light yellow-coloured colonies. Growth occurred at 15-30 °C (optimum, 20 °C), at pH 5.0-9.0 (optimum, pH 6.0) and with 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain STM-24T belonged to the genus Novosphingobium and was most closely related to Novosphingobium piscinae SLH-16T with sequence similarity of 98.4 %. The major fatty acids (>10 %) of strain STM-24T were C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The major 2-hydroxy fatty acid was C14 : 0 2-OH. The polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, sphingoglycolipid, phosphatidylcholine and several uncharacterized lipids. The major polyamine was spermidine. The major isoprenoid quinone was Q-10. The DNA G+C content was 69.1mol%. The DNA-DNA hybridization value for strain STM-24T with N.piscinae SLH-16T, Novosphingobium taihuense JCM 12465T and Novosphingobium subterraneum DSM 12447T was less than 55 %. Phenotypic characteristics of the novel strain also differed from those of the closest related species of the genus Novosphingobium. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain STM-24T represents a novel species in the genus Novosphingobium, for which the name Novosphingobium bradum sp. nov. is proposed. The type strain is STM-24T (=BCRC 80925T=LMG 29291T=KCTC 42984T).

Chitinibacter fontanus sp. nov., isolated from a spring.

A bacterial strain, designated STM-7T, was isolated from a spring in Taiwan and characterized using a polyphasic taxonomy approach. Cells of strain STM-7T were Gram-staining-negative, aerobic, poly-β-hydroxybutyrate-accumulating, motile by a single polar flagellum, rod-shaped, surrounded by a thick capsule and formed milky-white colonies. Growth occurred at 15-37 °C (optimum, 25-30 °C), at pH 6-8 (optimum, pH 6-7) and with 0-2 % NaCl (optimum, 0-1 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain STM-7T belonged to the genus Chitinibacter and was most closely related to Chitinibacter tainanensis S1T with a sequence similarity of 97.3 %. Strain STM-7T contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0 as the predominant fatty acids. The major hydroxyl fatty acids were C12 : 0 3-OH and C16 : 0 3-OH. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid, an uncharacterized glycolipid and an uncharacterized phospholipid. The major isoprenoid quinone was Q-8. The DNA G+C content of the genomic DNA was 52.4 mol%. The DNA-DNA hybridization value for strain STM-7T with Chitinibacter tainanensis BCRC 17254T was less than 47 %. On the basis of the phylogenetic inference and phenotypic data, strain STM-7T should be classified as a representative of a novel species, for which the name Chitinibacter fontanus sp. nov. is proposed. The type strain is STM-7T (=BCRC 80923T=LMG 29289T=KCTC 42982T).

Subsurface temperature trends in response to thermal water exploitation in the Jiashi Hot Spring, northeastern Taiwan

Temperature monitoring provides important information for the sustainable management of a geothermal field. Previous studies indicate that a decline in aquifer pressure is an obvious indicator of thermal water overexploitation. However, many thermal water producing aquifers display a subtle temperature change rather than a pressure decline. Due to the importance of monitoring temperature change, temperature detection is an important topic in the sustainable management of geothermal fields. In this study, we used borehole temperature-depth curves, obtained from boreholes measured over half-year intervals from 2011 to 2014, as well as the Mann–Kendall method, to determine trends for subsurface temperature within the Jiashi Hot Spring in Taiwan. Our results indicate that trends for subsurface temperature are related to hydrogeology and the flow field of groundwater. Groundwater/thermal water flow directions are impacted by the exploitation of thermal water in production wells, according to their depths and distributions, but pressure declines are not a dominant feature. Repeatedly measured borehole temperature-depths and their resultant curves provide important information for understanding trends in subsurface temperature change within a geothermal field.

Metabolic characteristics of dominant microbes and key rare species from an acidic hot spring in Taiwan revealed by metagenomics.

BackgroundMicrobial diversity and community structures in acidic hot springs have been characterized by 16S rRNA gene-based diversity surveys. However, our understanding regarding the interactions among microbes, or between microbes and environmental factors, remains limited.ResultsIn the present study, a metagenomic approach, followed by bioinformatics analyses, were used to predict interactions within the microbial ecosystem in Shi-Huang-Ping (SHP), an acidic hot spring in northern Taiwan. Characterizing environmental parameters and potential metabolic pathways highlighted the importance of carbon assimilatory pathways. Four distinct carbon assimilatory pathways were identified in five dominant genera of bacteria. Of those dominant carbon fixers, Hydrogenobaculum bacteria outcompeted other carbon assimilators and dominated the SHP, presumably due to their ability to metabolize hydrogen and to withstand an anaerobic environment with fluctuating temperatures. Furthermore, most dominant microbes were capable of metabolizing inorganic sulfur-related compounds (abundant in SHP). However, Acidithiobacillus ferrooxidans was the only species among key rare microbes with the capability to fix nitrogen, suggesting a key role in nitrogen cycling. In addition to potential metabolic interactions, based on the 16S rRNAs gene sequence of Nanoarchaeum-related and its potential host Ignicoccus-related archaea, as well as sequences of viruses and CRISPR arrays, we inferred that there were complex microbe-microbe interactions.ConclusionsOur study provided evidence that there were numerous microbe-microbe and microbe-environment interactions within the microbial community in an acidic hot spring. We proposed that Hydrogenobaculum bacteria were the dominant microbial genus, as they were able to metabolize hydrogen, assimilate carbon and live in an anaerobic environment with fluctuating temperatures.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2230-9) contains supplementary material, which is available to authorized users.

Geostatistical analysis for spatially characterizing hydrochemical features of springs in Taiwan

The Taiwan Island is abundant in spring resources. Many industries of spring spas highlight unique hydrochemical characteristics of springs because consumers frequently consider bathing in all kinds of natural springs with therapeutic and relaxing functions. This work adopted geostatistical approaches, ordinary kriging (OK) and sequential Gaussian simulation (sGs), to spatially explore hydrochemical features of springs in Taiwan and establish classifications of springwater. First, OK and sGs were used to determine chloride, sulfate and bicarbonate distributions of springs emerging from metamorphic and sedimentary rocks. Then, ratios of chloride, sulfate and bicarbonate equivalents per liter were calculated based on the determined distributions. Finally, various combinations of chloride, sulfate and bicarbonate were adopted to spatially characterize classifications of springwater. This research result indicates that OK and sGs are capable of spatially characterizing the hydrochemical features and classification uncertainty of springs. However, the smooth effect of OK underestimates high values and overestimates low values, reducing the difference among Cl−, SO42− and HCO3− in springwater. Meanwhile, sGs realizations not only present high spatial heterogeneity, but enhance the influence of dominant hydrochemical features on classifications of springwater. Furthermore, springwater emerging from metamorphic and sedimentary rock areas in Taiwan can be divided into eight categories based on combinations of determined chloride, sulfate and bicarbonate. The principal HCO3− water is the major springwater category. The subordinate springwater types include the principal HCO3− water with Cl− or HCO3− and the principal Cl− water with HCO3−.

First Report of Maize chlorotic mottle virus on Sweet Corn in Taiwan.

In February 2014, a severe disease on maize (Zea mays L.) broke out in the fields of central and southwestern Taiwan and caused yield losses in sweet corn production. Chlorotic spots first appeared at the base of infected leaves and later developed into systemic mottling. Diffused necrotic patches were also found on leaves or husks of the diseased plants. Moreover, severe rosetting and stunting accompanied by abnormalities in ear production were observed on mature plants. Eighteen leaf samples from symptomatic plants were collected and submitted to our Plant Diagnostic Clinic for virus diagnosis. All of the samples were first tested by reverse transcriptase (RT)-PCR to detect Maize stripe virus (MSpV) and by indirect ELISA to detect Maize dwarf mosaic virus (MDMV) or Sugarcane mosaic virus (SCMV), which were endemic to this area (1). Only 2 out of 18 samples were positive for MDMV, SCMV, or mixed infection of both viruses. Sap inoculation tests conducted on seedlings of sweet corn cv. Honey 236 indicated that the MDMV- and SCMV-negative samples still had an unknown pathogen causing original symptoms in the receptor plants. The isolate from Yunlin county reacted only with the antibody to Maize chlorotic mottle virus (MCMV) (AC Diagnostics, Fayetteville, AR) in ELISA. For further identification, the MCMV-specific primers (forward: MCMVg3514F-GGGAACAACCTGCTCCA; reverse MCMVg4014R-GGACACGGAGTACGAGA) were designed from the nucleotide sequence of MCMV coat protein (CP) gene. In RT-PCR using the AccuPower RT/PCR PreMix kit (Bioneer, Daejeon, Korea), an expected 500-bp DNA fragment was observed. This PCR product was cloned and its nucleotide sequence was determined by Mission Biotech Co., Taipei, Taiwan. BLAST analysis of the CP gene of the MCMV-Yunlin revealed the maximum nucleotide identities (99%) with Chinese Sichuan isolates (GenBank Accession No. JQ984270) and 98% identities to four Chinese Yunnan isolates (GU138674, JQ982468, JQ982469, and KF010583) and one Kenya isolate (JX286709), compared with 97% to Kansas isolate (X14736) and 96% to Nebraska isolate (EU358605). Subsequently, the complete nucleotide sequence of the viral genome (KJ782300) was determined from five overlapping DNA fragments obtained from independent RT-PCR amplification. The virus isolate was infectious to sweet corn cultivars Bai-long-wang, Devotion, SC-34, SC2015, and Zheng-zi-mi, on which similar symptoms were developed after mechanical inoculation. During the spring of 2014, a total of 224 sweet corn samples were collected from the epidemic areas of Taichung, Yunlin, Chiayi, and Kaohsiung counties. Samples (n= 161) reacted positive for MCMV in ELISA and/or RT-PCR. In the field survey, more than 20 adult thrips might be observed on an MCMV-infected plant. Two species of Frankliniella were found on maize plants: F. williamsi Hood and F. intonsa Trybom. Maize thrips (F. williamsi), an occasional pest of maize occurring during winter and spring in Taiwan, was characterized by its abdominal sternite II on which 1 or 2 discal setae of equal length with posteromarginal setae were borne (2). Samples with 1, 5, 10, and 30 F. williamsi collected in the field were tested by RT-PCR; MCMV was detectable not only in the pooled crushed bodies but also in a single maize thrips. This is the first report of MCMV occurrence on maize in Taiwan and of the virus transmitted by maize thrips.