GROWTH RESPONSE OF CHLAMYDOMONAS AND HAEMATOCOCCUS TO THE VOLATILE FATTY ACIDS

1960 ◽  
Vol 6 (6) ◽  
pp. 611-617 ◽  
Author(s):  
Raymond G. Stross

The first five straight-chain saturated fatty acids were tested to determine their effect on cell division of phytoflagellates. Chlamydomonas reinhardti Danseard and Haematococcus pluvialis Flotow were selected for measurement because of information available from similar studies of the long-chain acids. Cultures were grown at five concentrations of the sodium salt within the range of 0.5 to 10.0 mmoles/liter.Acetate stimulated the rate of cell division, while butyrate, the other acid with an even number of carbons, produced an inconsistent although negligible effect.The fatty acids with an odd number of carbons inhibited division of cells, with propionate being most and valerate least effective. Inhibition in these tests, in which initial pH was kept constant, was proportional to the initial concentration of the acid salt. Additional tests showed propionate inhibition to be approximately proportional to a calculated amount of undissociated acid in the medium. H. pluvialis was 9–12 times more sensitive than was C. reinhardti.The possibility of propionic acid inhibition of algae in acid lakes is discussed.

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 310
Author(s):  
Fabian Sandgruber ◽  
Annekathrin Gielsdorf ◽  
Anja C. Baur ◽  
Benjamin Schenz ◽  
Sandra Marie Müller ◽  
...  

The nutrient composition of 15 commercially available microalgae powders of Arthrospira platensis, Chlorella pyrenoidosa and vulgaris, Dunaliella salina, Haematococcus pluvialis, Tetraselmis chuii, and Aphanizomenon flos-aquae was analyzed. The Dunaliella salina powders were characterized by a high content of carbohydrates, saturated fatty acids (SFAs), omega-6-polyunsaturated fatty acids (n6-PUFAs), heavy metals, and α-tocopherol, whereas the protein amounts, essential amino acids (EAAs), omega-3-PUFAs (n3-PUFAs), vitamins, and minerals were low. In the powder of Haematococcus pluvialis, ten times higher amounts of carotenoids compared to all other analyzed powders were determined, yet it was low in vitamins D and E, protein, and EAAs, and the n6/n3-PUFAs ratio was comparably high. Vitamin B12, quantified as cobalamin, was below 0.02 mg/100 g dry weight (d.w.) in all studied powders. Based on our analysis, microalgae such as Aphanizomenon and Chlorella may contribute to an adequate intake of critical nutrients such as protein with a high content of EAAs, dietary fibers, n3-PUFAs, Ca, Fe, Mg, and Zn, as well as vitamin D and E. Yet, the nutritional value of Aphanizomenon flos-aquae was slightly decreased by high contents of SFAs. The present data show that microalgae are rich in valuable nutrients, but the macro- and micronutrient profiles differ strongly between and within species.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruiling Gao ◽  
Zifu Li ◽  
Xiaoqin Zhou ◽  
Wenjun Bao ◽  
Shikun Cheng ◽  
...  

Abstract Background Volatile fatty acids (VFAs) can be effective and promising alternate carbon sources for microbial lipid production by a few oleaginous yeasts. However, the severe inhibitory effect of high-content (> 10 g/L) VFAs on these yeasts has impeded the production of high lipid yields and their large-scale application. Slightly acidic conditions have been commonly adopted because they have been considered favorable to oleaginous yeast cultivation. However, the acidic pH environment further aggravates this inhibition because VFAs appear largely in an undissociated form under this condition. Alkaline conditions likely alleviate the severe inhibition of high-content VFAs by significantly increasing the dissociation degree of VFAs. This hypothesis should be verified through a systematic research. Results The combined effects of high acetic acid concentrations and alkaline conditions on VFA utilization, cell growth, and lipid accumulation of Yarrowia lipolytica were systematically investigated through batch cultures of Y. lipolytica by using high concentrations (30–110 g/L) of acetic acid as a carbon source at an initial pH ranging from 6 to 10. An initial pH of 8 was determined as optimal. The highest biomass and lipid production (37.14 and 10.11 g/L) were obtained with 70 g/L acetic acid, whereas cultures with > 70 g/L acetic acid had decreased biomass and lipid yield due to excessive anion accumulation. Feasibilities on high-content propionic acid, butyric acid, and mixed VFAs were compared and evaluated. Results indicated that YX/S and YL/S of cultures on butyric acid (0.570, 0.144) were comparable with those on acetic acid (0.578, 0.160) under alkaline conditions. The performance on propionic acid was much inferior to that on other acids. Mixed VFAs were more beneficial to fast adaptation and lipid production than single types of VFA. Furthermore, cultures on food waste (FW) and fruit and vegetable waste (FVW) fermentate were carried out and lipid production was effectively improved under this alkaline condition. The highest biomass and lipid production on FW fermentate reached 14.65 g/L (YX/S: 0.414) and 3.20 g/L (YL/S: 0.091) with a lipid content of 21.86%, respectively. By comparison, the highest biomass and lipid production on FVW fermentate were 11.84 g/L (YX/S: 0.534) and 3.08 g/L (YL/S: 0.139), respectively, with a lipid content of 26.02%. Conclusions This study assumed and verified that alkaline conditions (optimal pH 8) could effectively alleviate the lethal effect of high-content VFA on Y. lipolytica and significantly improve biomass and lipid production. These results could provide a new cultivation strategy to achieve simple utilizations of high-content VFAs and increase lipid production. Feasibilities on FW and FVW-derived VFAs were evaluated, and meaningful information was provided for practical applications.


Archaea ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Xue Yang ◽  
Xiang Liu ◽  
Si Chen ◽  
Guangmin Liu ◽  
Shuyan Wu ◽  
...  

Volatile fatty acids (VFAs) are preferred valuable resources, which can be produced from anaerobic digestion process. This study presents a novel technology using β-cyclodextrins (β-CD) pretreatment integrated alkaline method to enhance VFAs production from codigestion of food waste and sewage sludge. Experiment results showed that optimized ratio of food waste to sewage sludge was 3 : 2 because it provided adequate organic substance and seed microorganisms. Based on this optimized ratio, the integrated treatment of alkaline pH 10 and β-CD addition (0.2 g/g TS) performed the best enhancement on VFAs production, and the maximum VFAs production was 8631.7 mg/L which was 6.13, 1.38, and 1.57 times higher than that of control, initial pH 10, and 0.2 g β-CD/g TS treatment, respectively. Furthermore, the hydrolysis rate of protein and polysaccharides was greatly improved in integration treatment, which was 1.18–3.45 times higher than that of other tests. Though the VFAs production and hydrolysis of polymeric organics were highly enhanced, the primary bacterial communities with different treatments did not show substantial differences.


1965 ◽  
Vol 58 (3) ◽  
pp. 400-402 ◽  
Author(s):  
M. Sayeed Quraishi ◽  
A. J. Thorsteinson

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1009
Author(s):  
Gwon Woo Park ◽  
Seongsoo Son ◽  
Myounghoon Moon ◽  
Subin Sin ◽  
Kyoungseon Min ◽  
...  

Microbial lipid production from oleaginous yeasts is a promising process for the sustainable development of the microbial biodiesel industry. However, the feedstock cost poses an economic problem for the production of microbial biodiesel. After lipid extraction, yeast biomass can be used as an organic source for microbial biodiesel production. In this study, volatile fatty acids (VFAs), produced via anaerobic digestion of a lipid-extracted yeast (LEY) residue, were utilized as a carbon source for the yeast Cryptococcus curvatus. The response surface methodology was used to determine the initial pH and inoculum volume for the optimal VFA production. The experimental result for VFA concentration was 4.51 g/L at an initial pH of 9 and an inoculation 25%. The optimization results from the response surface methodology showed that the maximal VFA concentration was 4.58 g/L at an initial pH of 8.40 and an inoculation of 39.49%. This study indicates that VFAs from LEY can be used as a carbon source for microbial biodiesel production, with the potential to significantly reduce feedstock costs.


Author(s):  
Magdy Mohamed Ismail ◽  
Magdy Mohamed Ismail ◽  
Mohamed Abdou Mousa ◽  
Mohamed Ismail Abou-Dobara ◽  
Nawal Mohamed Refat

Rayeb milk (bio-stirred yogurt) samples were prepared from cow milk sesame milk or cow and sesame milk mixture (1:1) with or without adding sucrose (5%), honey (5%), fructose (2.5%) and sorbitol (1.5%) and using ABT-5 culture. Results showed levels of saturated fatty acids (SFA), short chain fatty acids (SCFA) and medium chain fatty acids (MCFA were lower whereas values of unsaturated fatty acids (USFA), monounsaturated fatty acids (MUSFA), polyunsaturated fatty acids (PUSFA) and long chain fatty acids (LCFA) were higher in sesame milk Rayeb than that of Rayeb manufactured from cow milk. Rayeb made from cow and sesame mixture had higher levels of antioxidant activity than Rayeb prepared from cow milk or sesame milk. The acidity, total solids and total volatile fatty acids values of Rayeb milk treatments contained sweeteners were higher than that of control. The addition of sweeteners decreased SFA, SCFA and MCFA and increased USFA, MUSFA, PUSFA, LCFA and antioxidant activity values of Rayeb milk. Essential fatty acids, linoleic acid (omega-6), α-linolenic acid (omega-3) and oleic acid (omega-9) greatly increased in Rayeb made from cow and sesame milk mixture. Adding sweeteners had the same effect. Fortification of Rayeb milk with sweeteners highly improved the smell, taste, mouth feel, texture and body evaluation scores.


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