A note on the optimality criteria for maximum biomass production in a fed-batch fermentor

Metagenomics has revealed hundreds of species in almost all microbiota. In a few well-studied cases, microbial communities have been observed to coordinate their metabolic fluxes. In principle, microbes can divide tasks to reap the benefits of specialization, as in human economies. However, the benefits and stability of an economy of microbial specialists are far from obvious. Here, we physically model the population dynamics of microbes that compete for steadily supplied resources. Importantly, we explicitly model the metabolic fluxes yielding cellular biomass production under the constraint of a limited enzyme budget. We find that population dynamics generally leads to the coexistence of different metabolic types. We establish that these microbial consortia act as cartels, whereby population dynamics pins down resource concentrations at values for which no other strategy can invade. Finally, we propose that at steady supply, cartels of competing strategies automatically yield maximum biomass, thereby achieving a collective optimum.

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Biomass Production and Pigment Accumulation in Kale Grown Under Increasing Photoperiods

HortScience ◽

10.21273/hortsci.41.3.603 ◽

2006 ◽

Vol 41 (3) ◽

pp. 603-606 ◽

Cited By ~ 13

Author(s):

Mark G. Lefsrud ◽

Dean A. Kopsell ◽

Robert M. Augé ◽

A.J. Both

Keyword(s):

Biomass Production ◽

Dry Mass ◽

Fresh Mass ◽

Vegetable Crops ◽

Maximum Accumulation ◽

Excellent Source ◽

Pigment Accumulation ◽

Mass Basis ◽

Maximum Biomass Production ◽

Β Carotene

Consumption of fruit and vegetable crops rich in lutein and β-carotene carotenoids is associated with reduced risk of cancers and aging eye diseases. Kale (Brassica oleracea L. var. acephala D.C.) ranks highest for lutein concentrations and is an excellent source of dietary carotenoids. Kale plants were grown under varied photoperiods to determine changes in the accumulation of fresh and dry biomass, chlorophyll a and b, and lutein and β-carotene carotenoids. The plants were cultured in a controlled environment using nutrient solutions under photoperiod treatments of 6, 12, 16, or 24 hours (continuous). Fresh and dry mass production increased linearly as photoperiod increased, reaching a maximum under the 24-hour photoperiod. Maximum accumulation of lutein, β-carotene, and chlorophyll b occurred under the 24-h photoperiod at 13.5, 10.4, and 58.6 mg/100 g fresh mass, respectively. However, maximum chlorophyll a (235.1 mg/100 g fresh mass) occurred under the 12-hour photoperiod. When β-carotene and lutein were measured on a dry mass basis, the maximum accumulation was shifted to the 16-hour photoperiod. An increase in photoperiod resulted in increased pigment accumulation, but maximum concentrations of pigments were not correlated with maximum biomass production.

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Yeast biomass production with potential for biological control: process strategies for increasing yield

Research Society and Development ◽

10.33448/rsd-v9i4.3057 ◽

2020 ◽

Vol 9 (4) ◽

pp. e169943057

Author(s):

Ana Paula Colares de Andrade ◽

Helder Levi da Silva ◽

Gustavo Adolfo Saavedra Pinto

Keyword(s):

Biological Control ◽

Carbon Source ◽

Biomass Production ◽

Batch Process ◽

Aeration Rate ◽

Total Biomass ◽

Fed Batch ◽

Promising Alternative ◽

Yeast Biomass ◽

Feed Medium

The quality of vegetable products is directly linked to the techniques used in the field, in order to ensure safe and healthy products to health. In this context, the use of yeasts with potential for biological control proved to be a promising alternative to assure the safety of these foods. Fermentation processes have been used to promote the development of many products, including the production of yeast biomass. The objective of this work was to verify the influence of the aeration rate and the fed batch process in the production of yeast biomass. A yeast strain with biological control potential, belonging to Embrapa's Semi-Arid crop collection, was subjected to simple batch cultivation and fed with different aeration rates (3, 4, 6 and 8 L.ar/min) and concentration of carbon source in the feed medium (200, 400 and 600 g/L). The highest biomass (6.99 g/L) after 24 hours of fermentation was observed in the experiment that used an aeration rate of 8 L.ar/min. Regarding the concentration of the carbon source in the feed medium, it was found that the concentration of 200 g/L favored a greater total biomass (11.21 g/L) and reduced the production of ethanol (0.65 g/L ), while the concentration of 600 g/L favored less biomass production (7.90 g/L) and higher ethanol production (9.26 g/L). Thus, it was found that the aeration rate and the fed batch process favor the fermentation strategy, as they contribute to the production of yeast biomass and the overall yield of the process.

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Utilization of Dairy Wastewater for Pollutants Removal and High Lipid Biomass Production by a Newly Isolated Microalgal Strains Chloromonas playfairii and Desmodesmus opoliensis

International Journal of Applied Sciences and Biotechnology ◽

10.3126/ijasbt.v3i4.13986 ◽

2015 ◽

Vol 3 (4) ◽

pp. 699-707 ◽

Cited By ~ 1

Author(s):

Mahendraperumal Guruvaiah ◽

Madhuri Narra ◽

Ekta Shah ◽

Jisha James ◽

Anil Kurchania

Keyword(s):

Biomass Production ◽

Dairy Wastewater ◽

Biofuel Production ◽

Processing Unit ◽

Microalgae Cultivation ◽

High Lipid ◽

Close Relationship ◽

Pollutants Removal ◽

Simple Column ◽

Maximum Biomass Production

Two new unicellular microalgal species from milk processing unit situated at Anand, India were screened and tested for their growth rate and nutrient removal capability under dairy wastewater at outdoor conditions in a simple column aeration photobioreactor. Results of 18s rRNA sequence analysis indicated that these strains have a close relationship with Chloromonas playfairii and Desmodesmus opoliensis named as SBC 2 and SBC 3, respectively. Both the strains removed more than 92% of ammonical nitrogen and 99% of total phosphorus, whereas COD and BOD reductions were found to be more than 95%. Maximum biomass production was 1.7 and 1.2 g L-1 and lipid content was 15 and 12%, respectively from SBC 2 and SBC 3 after 15 d cultivation. This study demonstrates the potential of algae based biofuel production by coupling wastewater treatment with microalgae cultivation for high lipid containing biomass production using Chloromonas playfairii and Desmodesmus opoliensis.Int J Appl Sci Biotechnol, Vol 3(4): 699-707

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