• Korean Journal of Ecology and Environment
• /
• v.41 no.1
• /
• pp.111-115
• /
• 2008

Direct effects of zooplankton grazing activities on the natural assemblage of bacterioplankton and algae were evaluated at monthly intervals, from June to October of 2000, in the middle part of the River Spree, Germany. We quantified bacterioplankton, algae, zooplankton abundance and measured carbon ingestion rates (CIRs) by zooplankton according to two zooplankton size classes: (i) micro zooplankton (MICZ), ranging in size from 30 to $150{\mu}m$ and including rotifers and nauplii, excluding protozoans and (ii) macrozooplankton (MACZ), larger than $150{\mu}m$ and including cladocerans and copepods. CIRs were measured using natural bacterial and algae communities in the zooplankton density manipulation experiments. Algae biomass (average${\pm}$SD: $377{\pm}306{\mu}gC\;L^{-1}$, n=5) was always higher than bacterial biomass ($36.7{\pm}9.9{\mu}gC\;L^{-1}$, n=5). Total zooplankton biomass varied from 19.8 to $137{\mu}gC\;L^{-1}$. Total mean biomass of zooplankton was $59.9{\pm}52.5{\mu}gC\;L^{-1}$ (average${\pm}$SD, n=5). Average MICZ biomass ($40.2{\pm}47.6{\mu}gC\;L^{-1}$ n=5) was nearly twofold higher than MACZ biomass ($19.6{\pm}20.6{\mu}gC\;L^{-1}$ n=5). Total zooplankton CIRs on algae (average${\pm}$SD: $56.6{\pm}26.4{\mu}gC\;L^{-1}\;day^{-1}$) were $\sim$fourfold higher than that on bacteria $(12.7{\pm}6.0{\mu}gC\;L^{-1}\;day^{-1})$. MICZ CIRs on bacteria $(7.0{\pm}2.8{\mu}gC\;L^{-1}\;day^{-1})$ and algae $(28.6{\pm}20.6{\mu}gC\;L^{-1}\;day^{-1})$ were slightly higher than MACZ CIRs. On average, MICZ accounted for 55.6 and 50.5% of total zooplankton grazing on bacteria and algae, respectively. Considering the MICZ and MACZ CIRs, the relative role of transferring carbon to higher trophic levels were nearly similar between both communities in the lake-river ecosystem.

• Applied Biological Chemistry
• /
• v.50 no.1
• /
• pp.1-5
• /
• 2007

For the purpose of application for biomass of Pleurotus eryngii, the optimum culture condition were tested. It was found that the optimum culture condition for spot culture of pleurotus eryngii were 24$^{\circ}C$ for 18 days with PDA medium. And the optimum culture condition of bioreactor for biomass were pH 5.5, 18$^{\circ}C$ and 27 days with PDMP broth. It was possible to artificial cultivation of mycelial from Pleurotus eryngii using bioreactor for biomass under the optimum conditions, and it was also possible for Pleurotus eryngii biomass because the forming of fruiting body when Pleurotus eryngii was cultivated using mass artificial cultivated mycelial in the bioreactor.

• Korean Journal of Ecology and Environment
• /
• v.46 no.2
• /
• pp.276-288
• /
• 2013

The present study investigates the effects of elevated soil nitrogen on growth and decomposition of Oryza sativa shoots. The plants were cultivated in greenhouse until leaf senescence and the total biomass of the plant increased 1.9 times at nitrogen addition plot. Total C and N content in shoot increased; however, lignin, C/N, and lignin/N levels decreased in the N-treated soil. The shoot litters collected from the control and N-treated soil were tested for decay and microbial biomass, $CO_2$ evolution, and enzyme activities during decomposition on the control and N-treated soil at $25^{\circ}C$ microcosm. The remaining mass of the shoot litter was approximately 6% higher in the litter collected from the control soil (53.0%) than the litter collected from high N-treated soil (47.1%). However, the high N-containing litter exhibited faster decay in the control soil than in the N-treated soil. The litter containing high N, low C/N, and low lignin/N showed a higher decomposition rate than that of low quality litter. The N-addition showed decreased microbial biomass C and dehydrogenase activity in soil; however, it exhibited high microbial biomass N and urease activity in soil. When the high N-containing litter decays on the N-treated soil, the microbial biomass C increased rapidly at the initial phase of decomposition and decreased thereafter, and dehydrogenase activity was less that of other treatment; however, there was no effect on the microbial biomass N. The urease in the decomposing litter was highest during the early decomposition stage and dramatically decreased thereafter. The present findings suggested that the N-addition increased N content in litter, but inhibited the decomposition process of above-ground biomass in terrestrial ecosystems.

• The Korean Journal of Ecology
• /
• v.27 no.4
• /
• pp.225-230
• /
• 2004

The impact of slash and burning on microbial biomass C, N and P in soils of semi-evergreen tropical deciduous forest were studied from February 1999 to January 2000. The experimental sites were located near Moreh town in the Chandel district of Manipur state (India) along the Indo-Myanmar border between 23° 49' N-24°28'N latitude and 93°45'E-94°16'E longitude. Microbial biomass C ranged from 319.50 ㎍ g/sup -1/ 905.50㎍ g/sup -1/ in the slash and burnt site and from 209.50 ㎍ g/sup -1/ to 708.80 ㎍ g/sup -1/ soil in the forest site. Microbial N ranged from 19.30 ㎍ g/sup -1/ to 99.45 ㎍ g/sup -1/ in the slash and burnt site and from 16.08㎍ g/sup -1/ to 88.90 ㎍ g/sup -1/ in the forest site. Microbial P varied from 10.90 ㎍ g/sup -1/ to 32.21 ㎍ g/sup -1/ in the slash and burnt site and from 2.50 ㎍ g/sup -1/ to 17.60 ㎍ g/sup -1/ in the forest site in different months throughout the year. Microbial biomass C, N and P were recorded to be higher in the slash and burnt site compared to the forest site The conversion of forest into slash and burnt site for agriculture - the traditional shilling cultivation practiced by tribal people in the north- eastern India leads to addition of large amount of organic matter in the soil thereby exhibiting higher values of microbial biomass C, N and P in the recent slash and burnt site than that of the forest site. Relationship between the soil moisture, soil organic C and microbial biomass C, N and P were found to be correlated significantly in both the sites.

• Journal of the korean society of oceanography
• /
• v.32 no.3
• /
• pp.145-155
• /
• 1997

The distribution of microzooplankton and hydrographic variables were measured in the Virginia portion of Chesapeake Bay and its major rivers. Samples were collected at 14 locations at monthly interval from September 1993 through December 1995. Ciliates were numerically dominated (>90%) and copepod nauplii comprised highest proportion of the total microzooplankton biomass (>77%). Copepod nauplii and ciliates were the most abundant at oligohaline water and rotifers at freshwater. Total microzooplankton density and biomass were usually higher at oligohaline stations than fresh water and polyhaline stations. Despite high nutrient concentration and phytoplankton density at eutrophic water, micro- and mesozooplankton biomass were low. Mesozooplankton were relatively abundant at polyhaline stations. The comparison between annual mean biomass of ciliates (12.7 ${\mu$}gC/1) and that of autotrophic picoplankton (13.5 {$\mu$}gC/1) revealed that ciliates were a major consumer of picoplankton production. The secondary production by ciliates was 12.7 ${\mu}$gC/1/day, representing 5% of the annual mean primary production in Chesapeake Bay, Total microzooplankton comprised 84% of the total zooplankton carbon content, representing five times higher than mesozooplankton biomass.

• Journal of Forest and Environmental Science
• /
• v.34 no.1
• /
• pp.12-23
• /
• 2018

Quantitative information on biomass and available nutrients are essential for developing sustainable forest management strategies to regulate atmospheric carbon. An attempt was made at Chilapatta Reserve Forest in Duars region of West Bengal to quantify its above and below ground carbon along with available "N", "P" and "K" in the soil. Stratified random nested quadrats were marked for soil, biomass and litter sampling. Indirect or non-destructive procedures were employed for biomass estimation. The amount of these available nutrients and organic carbon quantified in soil indicates that the forest soil is high in organic carbon and available "K" and medium in phosphorus and nitrogen. The biomass, soil carbon and total carbon (soil C＋C in plant biomass) in the forest was 1,995.98, 75.83 and $973.65Mg\;ha^{-1}$. More than 90% of the carbon accumulated in the forest was contributed by the trees. The annual litter production of the forest was $5.37Mg\;ha^{-1}$. Carbon accumulation is intricately linked with site quality factors. The estimated biomass of $1,995.98Mg{\cdot}ha^{-1}$ clearly indicates this. The site quality factor i.e. tropical moist deciduous with optimum availability of soil nutrients, heavy precipitation, high mean monthly relative humidity and optimum temperature range supported luxuriant growth which was realized as higher biomass accumulation and hence higher carbon accumulated.

• Journal of Life Science
• /
• v.25 no.12
• /
• pp.1450-1457
• /
• 2015

To overcome the depletion of fossil fuels and environmental problems in future, the research and production of biofuels have attracted attention largely. Thermophilic microorganisms produce effective and robust enzymes which can hydrolyze plant biomass and survive under harsh bioprocessing conditions. Caldicellulosiruptor bescii, which can degrade unpretreated plants and grow on them, is the one of the best candidates for consolidated bioprocessing (CBP). C. bescii can hydrolyze pectin efficiently as well as the major plant cell wall components, cellulose and hemicelluloses. Many glycosyl hydrolases and carbohydrate lyases with multidomain structure play an important role in plant biomass decomposition. Recently genetic tools for metabolic engineering of C. bescii have developed and bioethanol production from unpretreated biomass is achieved in C. bescii. Here, we review the recent studies for biomass degradation by C. bescii and bioethanol production in C. bescii in order to provide information about metabolic engineering of themophilic bacteria and biofuel development.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.6
• /
• pp.952-961
• /
• 2019

Chlorella spp. are green algae that are found across wide-ranging habitats from deserts to arctic regions, with various strains having adapted to survive under diverse environmental conditions. In this study, two novel Chlorella strains (ABC-002, ABC-008) were isolated from a freshwater lake in South Korea during the winter season and examined for possible use in the biofuel production process. The comparison of ABC-002 and ABC-008 strains with Chlorella vulgaris UTEX265 under two different temperatures ($10^{\circ}C$, $25^{\circ}C$) revealed their cold-tolerant phenotypes as well as high biomass yields. The maximum quantum yields of UTEX25, ABC-002, and ABC-008 at $10^{\circ}C$ were 0.5594, 0.6747, and 0.7150, respectively, providing evidence of the relatively higher cold-resistance capabilities of these two strains. Furthermore, both the biomass yields and lipid content of the two novel strains were found to be higher than those of UTEX265; the overall lipid productivities of ABC-002 and ABC-008 were 1.7 ~ 2.8 fold and 1.6 ~ 4.2 fold higher compared to that of UTEX265, respectively. Thus, the high biomass and lipid productivity over a wide range of temperatures indicate that C. vulgaris ABC-002 and ABC-008 are promising candidates for applications in biofuel productions via outdoor biomass cultivation.

• Transactions of the Korean hydrogen and new energy society
• /
• v.15 no.4
• /
• pp.309-316
• /
• 2004

Chlamydomonas reinhardtii UTEX 90 was cultivated with continuous supply of 2% $CO_2$ using TAP media at $25^\circ{C}$ and produced biomass 1.18 g of dry cell weight/L for 4 days. C. reinhardtii algal biomass(CAB) was concentrated to 20 times by volume and converted into hydrogen and organic acids by anaerobic fermentation using Clostridium butyricum. Organic acids in the fermentate of CAB were consecutively used to produce hydrogen by Rhodobacter sphaeroides KD 131 under the light condition. Approximately 52% of starch in the concentrated CAB which had 4-5.8, 24-26 and 6-7 g/L of starch, protein and fat, respectively was degraded by Cl. butyricum at $37^\circ{C}$. During this process, hydrogen and some organic acids, such as formate, acetate, propionate, and butyrate, respectively were produced. Further conversion of the organic acids in anaerobic fermentate of CAB by Rb. sphaeroides KD131 produced hydrogen from the anaerobic fermentate under the illumination of 8 klux using halogen lamp at $30^\circ{C}$. The result showed that hydrogen was evolved by the anaerobic conversion using Cl. butyricum and then by the photosynthetic fermentation using Rb. sphaeroides KD131. It indicated that the two-step conversion process produced the maximum amount of hydrogen from algal biomass which contained carbohydrate, protein, and fat via organic acids.

• Applied Biological Chemistry
• /
• v.49 no.4
• /
• pp.266-269
• /
• 2006

For the purpose of application for biomass of Tricholoma matsutake, the optimum culture condition were determined. It was found that the optimum culture condition for spot culture of Tricholoma matsutake were pH 5.5 and 3% brown rice meal at $24^{\circ}C$ for 35 days with MMN medium. And the optimum culture condition of bioreactor for biomass were $18^{\circ}C$ and 60 days with PDMP broth.