Effects of Additional Mg2+ on the Growth and Lipid Accumulation of Monoraphidium Sp. FXY-10 under Mixotrophic Conditions

2013 ◽  
Vol 860-863 ◽  
pp. 920-927
Author(s):  
Rao Qiong Che ◽  
Qiu Mei Wang ◽  
Li Huang ◽  
Peng Zhao ◽  
Xu Ya Yu

The effects of additional Mg2+ on the growth and lipid accumulation of the microalgae Monoraphidium sp. FXY-10 under mixotrophic conditions were investigated. 100 μmol Mg2+ were added to the growth media during the stationary growth phase. Compared with the control (35.25%), the highest lipid content reached up to 37.13% biomass after Mg2+ was added to the media. Moreover, the higher lipid productivity of 79.83 mg L1 d1 and the biomass productivity of 214.65 mg L1 d1 were attained in the Mg2+-supplemented cultures, as compared with cultures without supplemented (72.95 mg L1 d1 and 179.28 mg L1 d1, respectively). The use of Mg2+ supplements were proven to stimulate cell regrowth, prolong the stationary phase, and promote lipid accumulation in Monoraphidium sp. FXY-10.

2008 ◽  
Vol 74 (15) ◽  
pp. 4847-4852 ◽  
Author(s):  
Anastasia Matthies ◽  
Thomas Clavel ◽  
Michael Gütschow ◽  
Wolfram Engst ◽  
Dirk Haller ◽  
...  

ABSTRACT The metabolism of isoflavones by gut bacteria plays a key role in the availability and bioactivation of these compounds in the intestine. Daidzein and genistein are the most common dietary soy isoflavones. While daidzein conversion yielding equol has been known for some time, the corresponding formation of 5-hydroxy-equol from genistein has not been reported previously. We isolated a strictly anaerobic bacterium (Mt1B8) from the mouse intestine which converted daidzein via dihydrodaidzein to equol as well as genistein via dihydrogenistein to 5-hydroxy-equol. Strain Mt1B8 was a gram-positive, rod-shaped bacterium identified as a member of the Coriobacteriaceae. Strain Mt1B8 also transformed dihydrodaidzein and dihydrogenistein to equol and 5-hydroxy-equol, respectively. The conversion of daidzein, genistein, dihydrodaidzein, and dihydrogenistein in the stationary growth phase depended on preincubation with the corresponding isoflavonoid, indicating enzyme induction. Moreover, dihydrogenistein was transformed even more rapidly in the stationary phase when strain Mt1B8 was grown on either genistein or daidzein. Growing the cells on daidzein also enabled conversion of genistein. This suggests that the same enzymes are involved in the conversion of the two isoflavones.


2001 ◽  
Vol 69 (4) ◽  
pp. 2739-2742 ◽  
Author(s):  
Ramesh Ramamoorthy ◽  
Dorothy Scholl-Meeker

ABSTRACT Previously, we had demonstrated the upregulation in the expression of several proteins, including the lipoproteins OspC and P35, ofBorrelia burgdorferi in the stationary growth phase. Since the expression of OspC is also known to be affected by culture temperature and pH, we examined the effects of both variables on the expression of the remaining stationary-phase-upregulated proteins. Our study revealed that the expression of each of the remaining stationary-phase-upregulated proteins, P35 included, was also influenced by culture temperature; these proteins were selectively expressed at 34°C but not at 24°C. Significantly, the expression of a majority of these proteins was also affected by culture pH, since they were abundantly expressed at pH 7.0 (resembling the tick midgut pH of 6.8 during feeding) but only sparsely at pH 8.0 (a condition closer to that of the unfed tick midgut pH of 7.4). We propose that this group of B. burgdorferi proteins, which in culture is selectively expressed under conditions of 34°C and pH 7.0, may be induced in the tick midgut during the feeding event. Furthermore, the differential and coordinate expression of these proteins under different environmental conditions suggests that the encoding genes may be coregulated.


2009 ◽  
Vol 191 (9) ◽  
pp. 3177-3182 ◽  
Author(s):  
Ilana Kolodkin-Gal ◽  
Hanna Engelberg-Kulka

ABSTRACT Escherichia coli mazEF is a toxin-antitoxin gene module that mediates cell death during exponential-phase cellular growth through either reactive oxygen species (ROS)-dependent or ROS-independent pathways. Here, we found that the stationary-phase sigma factor σS was responsible for the resistance to mazEF-mediated cell death during stationary growth phase. Deletion of rpoS, the gene encoding σS from the bacterial chromosome, permitted mazEF-mediated cell death during stationary growth phase.


Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 413 ◽  
Author(s):  
Carla Avila ◽  
Simon Mule ◽  
Livia Rosa-Fernandes ◽  
Rosa Viner ◽  
María Barisón ◽  
...  

Trypanosoma cruzi, the etiologic agent of Chagas disease, cycles through different life stages characterized by defined molecular traits associated with the proliferative or differentiation state. In particular, T. cruzi epimastigotes are the replicative forms that colonize the intestine of the Triatomine insect vector before entering the stationary phase that is crucial for differentiation into metacyclic trypomastigotes, which are the infective forms of mammalian hosts. The transition from proliferative exponential phase to quiescent stationary phase represents an important step that recapitulates the early molecular events of metacyclogenesis, opening new possibilities for understanding this process. In this study, we report a quantitative shotgun proteomic analysis of the T. cruzi epimastigote in the exponential and stationary growth phases. More than 3000 proteins were detected and quantified, highlighting the regulation of proteins involved in different subcellular compartments. Ribosomal proteins were upregulated in the exponential phase, supporting the higher replication rate of this growth phase. Autophagy-related proteins were upregulated in the stationary growth phase, indicating the onset of the metacyclogenesis process. Moreover, this study reports the regulation of N-terminally acetylated proteins during growth phase transitioning, adding a new layer of regulation to this process. Taken together, this study reports a proteome-wide rewiring during T. cruzi transit from the replicative exponential phase to the stationary growth phase, which is the preparatory phase for differentiation.


2019 ◽  
Vol 11 (1) ◽  
pp. 10-14
Author(s):  
Larysa Cheban ◽  
Mykhailo Marchenko ◽  
Elvira Aleksa

The article is devoted to the study of the productivity of mixed cultures of microalgae Desmodesmus armatus (Chod.) Hegew. and Acutodesmus dimorphus (Turpin) Tsarenko. Algae were mixed in the following ratios: D/A (1:1), D/A (1:2) and D/A (2:1). The efficiency of mixed cultures growing was compared with that for monocultures of D. armatus and A. dimorphus. Mono- and mixed cultures of algae were grown in Tamiya for 21 days, in a climatic room. Every three days, the amount of biomass was analyzed according to the density of the culture. By the end of the stationary growth phase, the biomass productivity of mono- and mixed algal cultures was analyzed. It was noted that the largest amount of biomass accumulates in the mixed D/A culture (1:1) on the 12th day of cultivation. The nutrient content in the mixed cultures biomass depends on cultivation conditions and does not significantly differ from that for monocultures of both species. The highest amount of total protein was observed in the mixed D/A culture (1:1). The content of chlorophyll a and b differs slightly in the three variants of mixed cultures and is at the level of the monoculture indicator. The content of carotenoids conclusively decreased in 1.6 - 1.8 times in mixed cultures as compared to monocultures. The biomass of a mixed culture of D. armatus and A. dimorphus in a 1: 1 ratio can be used to grow the freshwater zooplankton.


2010 ◽  
Vol 8 (1) ◽  
pp. 51 ◽  
Author(s):  
Niurka Meneses ◽  
Guillermo Mendoza-Hernández ◽  
Sergio Encarnación

PROTEOMICS ◽  
2018 ◽  
Vol 18 (14) ◽  
pp. 1800116 ◽  
Author(s):  
Micaela Cerletti ◽  
María Ines Giménez ◽  
Christian Tröetschel ◽  
Celeste D’ Alessandro ◽  
Ansgar Poetsch ◽  
...  

1979 ◽  
Vol 42 (11) ◽  
pp. 848-851 ◽  
Author(s):  
Y. PARK ◽  
E. M. MIKOLAJCIK

Growth and alpha toxin production by a strain of Clostridium perfringens was determined in Thioglycollate medium, beef broth with ground beef, and beef broth with ground beef and soy protein. Incubation temperatures ranged from 15 to 50 C. In Thioglycollate medium, maximum alpha toxin production occurred at 35 C and was 40 times greater than that observed at 45 C. However, generation time and maximum population were approximately the same at 35 and 45 C. At 15 C, a two log cycle reduction in viable counts occurred within 6 h. Irrespective of incubation temperature, alpha toxin levels in Thioglycollate medium declined as the incubation period was extended beyond the stationary growth phase. In the beef broth with ground beef system which was studied at 35 C only, the organism grew slower and produced less toxin than in Thioglycollate medium. The amount of alpha toxin detected was influenced to a greater extent by the incubation time and temperature, the holding time beyond the stationary growth phase, and the growth medium than by the population level of C. perfringens.


RNA Biology ◽  
2016 ◽  
Vol 13 (4) ◽  
pp. 427-440 ◽  
Author(s):  
Efthimia Lioliou ◽  
Pierre Fechter ◽  
Isabelle Caldelari ◽  
Brian C. Jester ◽  
Sarah Dubrac ◽  
...  

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