• Korean Journal of Plant Tissue Culture
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• v.28 no.3
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• pp.117-121
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• 2001

Microstructure of abaxial leaf surface and carbohydrate content of propagules grown in different culture conditions such as heterotrophic, mixotrophic and autotrophic carbon source were investigated. In the leaves of propagules which were grown in the green house, autotrophic and mixotrophic conditions, wax layer was observed, but in the leaves of the heterotrophic propagules, it was not observed. Size and number of stomata of the leaves in the heterotrophic condition was larger and more numerous than that of autotrophic propagules. Especially, stomata of the leaves in the autotrophic condition was similar to the leaves of plant grown in green house. Carbohydrate content was higher in photoautotrophic condition than that in mixotrophic and heterotrophic culture. Also, Free sugar content showed higher in photoautotrophic propagules than that in mixotrophic and heterotrophic culture. In all the culture conditions, content of glucose were higher than that of other free sugars.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.703-709
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• 2013

Among many microalgae cultivation types, heterotrophic culture with low cost carbon sources and energy saving culture method is crucial. A result of estimating the effects of pH on wastewater treatment using heterotrophic growing microalgae Chlorella sorokiniana shows that there was no difference in microalgae growth amount and nitrogen, phosphorus removal rate by wide range of pH(5 ~ 9). From pH 5 to 9, total nitrogen, phosphorous and glucose removal rates were 10.5 mg-N/L/d, 2 mg-P/L/d, 800 ~ 1000 mg/L respectively. This study reveals that C. sorokiniana cannot metabolite glycerol heterotrophically, however, glucose and acetate were proper carbon sources for growth and T-N, T-P and TOC removal. This research highlights the potential of heterotrophic microalgal growth with wastewater treatment plant with wide range of pH and carbon sources.

• ALGAE
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• v.28 no.1
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• pp.101-109
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• 2013

Some Chlorella species grow heterotrophically with organic substrate in dark condition. However, heterotrophic Chlorella species are limited and their optimum culture conditions are not fully known. In this study, three heterotrophic Chlorella species, two strains (C4-3 and C4-4) of C. vulgaris and one Chlorella sp. (C4-8) were examined on optimum culture conditions such as carbon source, temperature, and concentrations of nitrogen and phosphorus in Jaworski's medium (JM). And the growth and fatty acid composition of Chlorella were analyzed. For three heterotrophic Chlorella species, glucose (1-2%) as a carbon source only increased the growth and the range of optimum culture temperature was $26-28^{\circ}C$. Doubled concentrations of the nitrogen or phosphorus in JM medium also improved the growth of Chlorella. Chlorella cultured heterotrophically showed significantly higher growth rate and bigger cell size than those autotrophically did. C. vulgaris (C4-3) cultured heterotrophically showed the highest biomass in dry weight ($0.8g\;L^{-1}$) among three species. With respect to fatty acid composition, the contents of C16:0 and n-3 highly unsaturated fatty acid (HUFA) were significantly higher in autotrophic Chlorella than in heterotrophic one and those of total lipid were not different between different concentrations of nitrogen and phosphorus in JM medium. Among three Chlorella species in this study, C. vulgaris (C4-3) appeared to be the most ideal heterotrophic Chlorella species for industrial application since it had a high biomass and lipid content.

• Environmental Engineering Research
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• v.24 no.2
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• pp.309-317
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• 2019

This study evaluated the kinetics of acrylamide (AM) biodegradation by mixed culture bacteria and Enterobacter aerogenes (E. aerogenes) in sequencing batch reactor (SBR) systems with AQUASIM and linear regression. The zero-order, first-order, and Monod kinetic models were used to evaluate the kinetic parameters of both autotrophic and heterotrophic nitrifications and both AM and chemical oxygen demand (COD) removals at different AM concentrations of 100, 200, 300, and 400 mg AM/L. The results revealed that both autotrophic and heterotrophic nitrifications and both AM and COD removals followed the Monod kinetics. High AM loadings resulted in the transformation of Monod kinetics to the first-order reaction for AM and COD removals as the results of the compositions of mixed substrates and the inhibition of the free ammonia nitrogen (FAN). The kinetic parameters indicated that E. aerogenes degraded AM and COD at higher rates than mixed culture bacteria. The FAN from the AM biodegradation increased both heterotrophic and autotrophic nitrification rates at the AM concentrations of 100-300 mg AM/L. At higher AM concentrations, the FAN accumulated in the SBR system inhibited the autotrophic nitrification of mixed culture bacteria. The accumulation of intracellular polyphosphate caused the heterotrophic nitrification of E. aerogenes to follow the first-order approximation.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.91-95
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• 2001

Propagules grown at different in vitro culture conditions such as heterotrophic, mixotrophic and photoautotrophic conditions were investigated for growth, total photosynthesis ratio and flowering. Survival rate of propagules after transplanting was higher in photoautotrophic propagules than in the heterotrophic and mixotrophic ones. Total photosynthesis was higher plantlets growth in photoautotrophic (154 mg$CO_2$.mgDW$^{-1}$ h$^{-2}$ ) those grown than in mixotrphpic (148 mg$CO_2$.mgDW$^{-1}$ h$^{-2}$ ) and heterotrophic (102 mg$CO_2$.mgDW$^{-1}$ h$^{-2}$ ) 30 days after transplanting into fields. Day to flowering of the plant cultured in photoautotrophic condition was shortened by 7~10 days than those of heterotrophic and mixotrophic ones. Length of the petiole, number of leaves, leaf area and chlorophyll content were also increased.

• Microbiology and Biotechnology Letters
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• v.35 no.1
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• pp.45-51
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• 2007

Arthrospira (Spirulina) platensis is one of the commercially important filamentous cyanobacteria. The heterotrophic cultivation of Arthrospira can be an alternative strategy for commercial mass production. In heterotrophic culture, the specific growth rate of A. platensis M9108, a glucose-resistant mutant of A. platensis PCC 9108, was $0.014h^{-1}$ which was 1.8 higher than that oi the previous report. The mutant possessed the facility to assimilate and to metabolize glucose efficiently under heterotrophic condition. However, the r-linolenic acid content of 6 Arthrospira strains was not increased in heterotrophic culture. Four Arthrospira strains out of 6 tested strains were able to utilize maltose as a carbon source under heterotrophic condition. The biomass production of these strains on maltose was similar to that on glucose. The specific growth rate of A. platensis M9108 increased with glucose concentration up to 5.0 g/L and then decreased at a glucose concentration of 10.0 g/L. Additionally, A. platensis M9108 under heterotrophic condition showed no aggregation during the cultivation in contrast to A. platensis PCC 9108.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.222-228
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• 2022

As a possible feedstock for biodiesel, the marine green alga Tetraselmis sp. was cultivated under different conditions of phototrophic, mixotrophic and heterotrophic cultures. Glycerol, a byproduct from biodiesel production process, was used as the carbon source of mixotrophic and heterotrophic culture. The effects of glycerol supply and nitrate-repletion were compared for different trophic conditions. Mixotrophic cultivation exhibited higher biomass productivity than that of phototrophic and heterotrophic cultivation. Maximum lipid productivity of 55.5 mg L^-1 d^-1 was obtained in the mixotrophic culture with 5 g L^-1 of glycerol and 8.8 mM of nitrate due to the enhancement of both biomass and lipid accumulation. The major fatty acid methyl esters (FAME) in the produced biodiesel were palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2), and linolenic acid (C18:3). The degree of unsaturation was affected by different culture conditions. The biodiesel properties predicted by correlation equations based on the FAME profiles mostly complied with the specifications from the US, Europe and Korea, with the exception of the cold-filter plugging point (CFPP) criterion of Korea.

• Fisheries and Aquatic Sciences
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• v.7 no.1
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• pp.34-38
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• 2004

The heterotrophic production method for Tetraselmis suecica, a suggested alternative to photoautotrophic one in the economic sense, was studied in terms of cell growth and sterolic property. The alga in the 10 mM organic carbon (glucose) manifested cell growth. However, the alga produced by the heterotrophic method showed a unique property of sterol determined with an aid of GC and GC-MS. The photoautotrophic control T. suecica contained 6 detectable sterol species: $cholesta-5,\;22-dien-3\beta-o1$, $ergost-5-en-3\beta-o1$, cholest-5-en-3\beta-o1$, $24-methyl-cholesta-5,\;22-dien-3\beta-o1$, $24-methylcholesta-5,\;24-dien-3\beta-o1$, $24-ethylchlolesta-5,\;24-dien-3\beta­o1$, $24-methylcholesta-5-en-3\beta-o1$, and $24-ethylchlolesta-5en-3\beta-o1$. We discuss the sterolic properties of the alga along the heterotrophic progress, particularly focusing on the availability of the method in the aquaculture of bivalves which normally need sterols as a dietary source.

• KSBB Journal
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• v.29 no.1
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• pp.72-80
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• 2014

CW-4Y was identified as Stenotrophomonas sp. by morphological and physiological characteristics, and phylogenetic analysis of its 16S rDNA gene sequence. Nitrogen removal by CW-4Y was analyzed in relation to the ammonium concentration, presence of organic carbon, carbon source, and carbon-to-nitrogen ratio (C/N). Stenotrophomonas CW-4Y has heterotrophic nitrification and aerobic denitrification abilities. Stenotrophomonas CW-4Y utilized only glucose as carbon sources, and heterotrophic nitrification and aerobic denitrification were observed regardless of the type of nitrogen source. The maximum ammonium removal rate of CW-4Y was 80 $mg-N{\cdot}L^{-1}{\cdot}d^{-1}$ and its denitrification rate of 192 $mg-N{\cdot}L^{-1}{\cdot}d^{-1}$ at $NO_3{^-}-N$ (about 280 ppm) in shake culture experiments at a C/N ratio of about 15 was about 30 times higher than those of other bacteria with the same ability.

• ALGAE
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• v.37 no.2
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• pp.149-161
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• 2022

Noctiluca scintillans is a heterotrophic dinoflagellate that causes red-colored oceans during the day (red tides) and glowing oceans at night (bioluminescence). This species feeds on diverse prey, including phytoplankton, heterotrophic protists, and eggs of metazoans. Thus, many scientists have conducted studies on the ecophysiology of this species. It is easy to cultivate N. scintillans at a scale of <1 L, but it is difficult to cultivate them at a scale of >100 L because N. scintillans cells usually stay near the surface, while prey cells stay below the surface in large water tanks. To obtain mass-cultured N. scintillans cells, we developed an automatic system for cultivating N. scintillans on a scale of 100 L. The system consisted of four tanks containing fresh nutrients, the chlorophyte Dunaliella salina as prey, N. scintillans for growth, and N. scintillans for storage, respectively. The light intensities supporting the high growth rates of D. salina and N. scintillans were 300 and 20 µmol photons m^-2 s^-1, respectively. Twenty liters of D. salina culture from the prey culture tank were transferred to the predator culture tank, and subsequently 20 L of nutrients from the nutrient tank were transferred to the prey culture tank every 2 d. When the volume of N. scintillans in the predator culture tank reached 90 L 6 d later, 70 L of the culture were transferred to the predator storage tank. To prevent N. scintillans cells from being separated from D. salina cells in the predator culture tank, the culture was mixed using an air pump, a sparger, and a stirrer. The highest abundance of N. scintillans in the predator culture tank was 45 cells mL^-1, which was more than twice the highest abundance when this dinoflagellate was cultivated manually. This automatic system supplies 100 L of N. scintillans pure culture with a high density every 10 d for diverse experiments on N. scintillans.