scholarly journals Screening of an adapted culture medium composed by different carbon sources for heterotrophic cultivation of Chlorella vulgaris using a microplate assay

2018 ◽  
Vol 40 (1) ◽  
pp. 39401 ◽  
Author(s):  
Gustavo Graciano Fonseca ◽  
Alisson Alves da Silva
Keyword(s):  
Chlorella Vulgaris ◽  
Culture Medium ◽  
Carbon Sources ◽  
Microplate Assay ◽  
Heterotrophic Cultivation

scholarly journals Effect of Different Cultivation Modes (Photoautotrophic, Mixotrophic, and Heterotrophic) on the Growth of Chlorella sp. and Biocompositions

2021 ◽  
Vol 9 ◽  
Author(s):  
Hyun-Sik Yun ◽  
Young-Saeng Kim ◽  
Ho-Sung Yoon
Keyword(s):  
Chlorella Vulgaris ◽  
Lipid Content ◽  
Inorganic Carbon ◽  
Biomass Yield ◽  
Carbon Sources ◽  
Biomass Productivity ◽  
Chlorella Sorokiniana ◽  
Raw Material ◽  
Heterotrophic Cultivation ◽  
Mixotrophic Conditions

In the past, biomass production using microalgae culture was dependent on inorganic carbon sources as microalgae are photosynthetic organisms. However, microalgae utilize both organic and inorganic carbon sources, such as glucose. Glucose is an excellent source of organic carbon that enhances biomass yield and the content of useful substances in microalgae. In this study, photoautotrophic, mixotrophic, and heterotrophic cultivation conditions were applied to three well-known strains of Chlorella (KNUA104, KNUA114, and KNUA122) to assess biomass productivity, and compositional changes (lipid, protein, and pigment) were evaluated in BG11 media under photoautotrophic, mixotrophic, and heterotrophic conditions utilizing different initial concentrations of glucose (5, 10, 15, 20, and 25 g L−1). Compared to the photoautotrophic condition (biomass yield: KNUA104, 0.35 ± 0.04 g/L/d; KNUA114, 0.40 ± 0.08 g/L/d; KNUA122, 0.38 ± 0.05 g/L/d) glucose was absent, and the biomass yield improved in the mixotrophic (glucose: 20 g L−1; biomass yield: KNUA104, 2.99 ± 0.10 g/L/d; KNUA114, 5.18 ± 0.81 g/L/d; KNUA122, 5.07 ± 0.22 g/L/d) and heterotrophic conditions (glucose: 20 g L−1; biomass yield: KNUA104, 1.72 ± 0.26 g/L/d; KNUA114, 4.26 ± 0.27 g/L/d; KNUA122, 4.32 ± 0.32 g/L/d). All strains under mixotrophic and heterotrophic conditions were optimally cultured when 15–20 g L−1 initial glucose was provided. Although bioresourse productivity improved under both mixotrophic and heterotrophic conditions where mixotrophic conditions were found to be optimal as the yields of lipid and pigment were also enhanced. Protein content was less affected by the presence of light or the concentration of glucose. Under mixotrophic conditions, the highest lipid content (glucose: 15 g L−1; lipid content: 68.80 ± 0.54%) was obtained with Chlorella vulgaris KNUA104, and enhanced pigment productivity of Chlorella sorokiniana KNUA114 and KNUA122 (additional pigment yield obtained with 15 g L−1 glucose: KNUA 114, 0.33 ± 0.01 g L−1; KNUA122, 0.21 ± 0.01 g L−1). Also, saturated fatty acid (SFA) content was enhanced in all strains (SFA: KNUA104, 29.76 ± 1.31%; KNUA114, 37.01 ± 0.98%; KNUA122, 33.37 ± 0.17%) under mixotrophic conditions. These results suggest that mixotrophic cultivation of Chlorella vulgaris and Chlorella sorokiniana could improve biomass yield and the raw material quality of biomass.

scholarly journals Improvement of the Culture Medium for the Dichlorvos-Ammonia (DV-AM) Method to Selectively Detect Aflatoxigenic Fungi in Soil

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 519 ◽  
Author(s):  
Kimiko Yabe ◽  
Haruna Ozaki ◽  
Takuya Maruyama ◽  
Keisuke Hayashi ◽  
Yuki Matto ◽  
...  
Keyword(s):  
Culture Medium ◽  
Agar Medium ◽  
Carbon Sources ◽  
Tween 80 ◽  
Selective Medium ◽  
Selective Detection ◽  
Aflatoxigenic Fungi ◽  
Aspergillus Nomius ◽  
Rhizopus Sp ◽  
Triton X

The dichlorvos-ammonia (DV-AM) method is a simple but sensitive visual method for detecting aflatoxigenic fungi. Here we sought to develop a selective medium that is appropriate for the growth of aflatoxigenic fungi among soil mycoflora. We examined the effects of different concentrations of carbon sources (sucrose and glucose) and detergents (deoxycholate (DOC), Triton X-100, and Tween 80) on microorganisms in soils, using agar medium supplemented with chloramphenicol. The results demonstrated that 5–10% sucrose concentrations and 0.1–0.15% DOC concentrations were appropriate for the selective detection of aflatoxigenic fungi in soil. We also identified the optimal constituents of the medium on which the normal rapid growth of Rhizopus sp. was completely inhibited. By using the new medium along with the DV-AM method, we succeeded in the isolation of aflatoxigenic fungi from non-agricultural fields in Fukui city, Japan. The fungi were identified as Aspergillus nomius based on their calmodulin gene sequences. These results indicate that the new medium will be useful in practice for the detection of aflatoxigenic fungi in soil samples including those from non-agricultural environments.

scholarly journals Polyhydroxyalkanoates production by a bacterium isolated from mangrove soil samples collected from Quang Ninh province

2012 ◽  
Vol 3 (2) ◽  
pp. 76-79 ◽  
Author(s):  
Thuoc Van Doan ◽  
Binh Thi Nguyen
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Culture Medium ◽  
Carbon Sources ◽  
Nile Red ◽  
Soil Samples ◽  
Mangrove Soil ◽  
Transmission Electron ◽  
Bacterium Strain ◽  
Quang Ninh

A PHA producing bacterium (strain QN271) was selected from mangrove soil samples collected from Quang Ninh province by using the Nile red dying technique. PHA accumulation in the selected bacterium strain was confirmed by transmission electron microscope. With the exception of maltose or sucrose, the bacterium strain was found to be able to synthesize PHA from various carbon sources (glucose, xylose, fructose, glycerol, and glucose plus propionate). The strain accumulated poly(3-hydroxybutyrate) from glucose, fructose, xylose, and glycerol whereas poly(3-hydroxybutyrate-co-3-hydroxyvalarate) was produced when a combination of glucose and propionate was included in the culture medium. Fructose was found to be most suitable substrate for PHA synthesis by strain QN271. PHA content of 63.3% and CDW of 6 g/L were obtained after 32 hrs of cultivation in fructose medium. Chủng vi khuẩn có khả năng sinh tổng hợp PHA đã được phân lập từ đất rừng ngập mặn tỉnh Quảng Ninh nhờ kỹ thuật nhuộm với Nile red. Ảnh quan sát dưới kính hiển vi điện tử dẫn truyền chứng tỏ rằng chủng vi khuẩn này có khả năng tích lũy lượng lớn PHA trong tế bào. Chủng vi khuẩn tuyển chọn có khả năng sinh tổng hợp PHA từ nhiều nguồn các bon khác nhau như glucose, xylose, fructose, glucerol, glucose và propionate nhưng không có khả năng tổng hợp PHA từ maltose hoặc saccharose. Chủng vi khuẩn tuyển chọn tổng hợp poly (3-hydroxybutyrate) từ các nguồn các-bon như glucose, xylose, fructose, hay glycerol, trong khi đó poly (3-hydroxybutyrate-co-3-hydroxyvalarate) sẽ được tổng hợp khi phối hợp sử dụng hai nguồn các-bon (glucose và propionate). Fructose là nguồn các-bon tốt nhất cho chủng QN271 sinh tổng hợp PHA, khi nuôi cấy trong môi trường có fructose chủng vi khuẩn này có thể tạo ra lượng sinh khối là 6 g/L trong đó có chứa 63.3% PHA sau 32 giờ.

Isolation of estrogen-degrading bacteria from an activated sludge bioreactor treating swine waste, including a strain that converts estrone to β-estradiol

2011 ◽  
Vol 57 (7) ◽  
pp. 559-568 ◽  
Author(s):  
Martine Isabelle ◽  
Richard Villemur ◽  
Pierre Juteau ◽  
François Lépine
Keyword(s):  
Carbon Source ◽  
Culture Medium ◽  
Agar Medium ◽  
Carbon Sources ◽  
Bacterial Consortium ◽  
Swine Wastewater ◽  
Low Concentrations ◽  
Degrading Bacteria ◽  
17Β Estradiol ◽  
Reducing Activity

An estrogen-degrading bacterial consortium from a swine wastewater biotreatment was enriched in the presence of low concentrations (1 mg/L) of estrone (E1), 17β-estradiol (βE2), and equol (EQO) as sole carbon sources. The consortium removed 99% ± 1% of these three estrogens in 48 h. Estrogen removal occurred even in the presence of an ammonia monooxygenase inhibitor, suggesting that nitrifiers are not involved. Five strains showing estrogen-metabolizing activity were isolated from the consortium on mineral agar medium with estrogens as sole carbon source. They are related to four genera ( Methylobacterium (strain MI6.1R), Ochrobactrum (strains MI6.1B and MI9.3), Pseudomonas (strain MI14.1), and Mycobacterium (strain MI21.2)) distributed among three classes (Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria). Depending on the culture medium, strains MI6.1B, MI9.3, MI14.1, and MI21.2 partially transform βE2 into E1, whereas Methylobacterium sp. strain MI6.1R reduces E1 into βE2 under aerobic conditions, in contrast with the usually observed conversion of βE2 into E1. Since βE2 is a more potent endocrine disruptor than E1, it means that the presence of Methylobacterium sp. strain MI6.1R (or other bacteria with the same E1-reducing activity) in a treatment could transiently increase the estrogenicity of the effluent. MI6.1R can also reduce the ketone group of 16-ketoestradiol, a hydroxylated analog of E1. All βE2 and E1 transformation activities were constitutive, and many of them are favoured in a rich medium than a medium containing no other carbon source. None of the isolated strains could degrade EQO.

scholarly journals Development of an Organic Culture Medium for Autotrophic Production of Chlorella vulgaris Biomass

2020 ◽  
Vol 10 (6) ◽  
pp. 2156
Author(s):  
Adriana Machado ◽  
Hugo Pereira ◽  
Margarida Costa ◽  
Tamára Santos ◽  
Bernardo Carvalho ◽  
...  
Keyword(s):  
Growth Performance ◽  
Chlorella Vulgaris ◽  
Culture Medium ◽  
Bubble Column ◽  
Organic Medium ◽  
Organic Substrates ◽  
Microalgal Biomass ◽  
Organic C ◽  
Certified Organic ◽  
Organic Culture

Microalgal biomass has gained increasing attention in the last decade for various biotechnological applications, including human nutrition. Certified organic products are currently a growing niche market in which the food industry has shown great interest. In this context, this work aimed at developing a certified organic culture medium for the production of autotrophic Chlorella vulgaris biomass. A preliminary assay in 2 L bubble column photobioreactors was performed in order to screen different commercial organic substrates (OS) at a normalized concentration of N (2 mmol L−1). The highest growth performance was obtained using EcoMix4 and Bioscape which showed similar biomass concentrations compared to the synthetic culture medium (control). In order to meet the nutrient needs of Chlorella, both OS underwent elemental analyses to assess their nutrient composition. The laboratory findings allowed the development of a final organic culture medium using a proportion of Bioscape/EcoMix4 (1:1.2, m/m). This organic culture medium was later validated outdoors in 125 L flat panel and 10 m3 tubular flow through photobioreactors. The results obtained revealed that the developed organic medium led to similar microalgal growth performance and biochemical composition of produced biomass, as compared to the traditional synthetic medium. Overall, the formulated organic medium was effective for the autotrophic production of organic C. vulgaris biomass.

scholarly journals Production of the Polysaccharide Curdlan by Agrobacterium species on Processing Coproducts and Plant Lignocellulosic Hydrolysates

Fermentation ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 16 ◽  
Author(s):  
Thomas P. West
Keyword(s):  
Culture Medium ◽  
Plant Biomass ◽  
Regulatory Protein ◽  
Carbon Sources ◽  
Growth Conditions ◽  
Chemical Mutagenesis ◽  
Selection Procedures ◽  
Lignocellulosic Hydrolysates ◽  
Prairie Cordgrass ◽  
Curdlan Production

This review examines the production of the biopolymer curdlan, synthesized by Agrobacterium species (sp.), on processing coproducts and plant lignocellulosic hydrolysates. Curdlan is a β-(1→3)-D-glucan that has various food, non-food and biomedical applications. A number of carbon sources support bacterial curdlan production upon depletion of nitrogen in the culture medium. The influence of culture medium pH is critical to the synthesis of curdlan. The biosynthesis of the β-(1→3)-D-glucan is likely controlled by a regulatory protein that controls the genes involved in the bacterial production of curdlan. Curdlan overproducer mutant strains have been isolated from Agrobacterium sp. ATCC 31749 and ATCC 31750 by chemical mutagenesis and different selection procedures. Several processing coproducts of crops have been utilized to support the production of curdlan. Of the processing coproducts investigated, cassava starch waste hydrolysate as a carbon source or wheat bran as a nitrogen source supported the highest curdlan production by ATCC 31749 grown at 30 °C. To a lesser extent, plant biomass hydrolysates have been explored as possible substrates for curdlan production by ATCC 31749. Prairie cordgrass hydrolysates have been shown to support curdlan production by ATCC 31749 although a curdlan overproducer mutant strain, derived from ATCC 31749, was shown to support nearly double the level of ATCC 31749 curdlan production under the same growth conditions.

Sucrose metabolism in Zymomonas mobilis: production and localization of sucrase and levansucrase activities

1990 ◽  
Vol 36 (3) ◽  
pp. 159-163 ◽  
Author(s):  
L. Preziosi ◽  
G. P. F. Michel ◽  
J. Baratti
Keyword(s):  
Key Words ◽  
Zymomonas Mobilis ◽  
Culture Medium ◽  
Carbon Sources ◽  
Cell Lysis ◽  
Sucrose Metabolism ◽  
Cellular Activity ◽  
Sucrase Activity ◽  
Membrane Bound ◽  
Kinetics Of

The sucrase and levansucrase activities of Zymomonas mobilis cells were characterized. The kinetics of production of sucrase activity was growth associated and the activity was constitutively expressed in cells grown on sucrose, glucose, or fructose media. Most of the sucrase activity (about 80%) was soluble and extracellular, while the cellular activity (about 20%) was demonstrated to be mostly membrane bound. The occurrence of sucrase activity in culture medium seemed to result from a secretory mechanism rather than from cell lysis. Like sucrase activity, levansucrase activity was mainly extracellular and was present in fermentations run with the above three carbon sources. These results demonstrated that both sucrase and levansucrase activities were present in cellular and extracellular extracts of cells grown on different sugars. Key words: Zymomonas mobilis, levansucrase, sucrase, localization.

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