Effects of carbon/nitrogen ratio, dissolved oxygen and impeller type on gellan gum production in Sphingomonas paucimobilis

2011 ◽  
Vol 62 (1) ◽  
pp. 299-305 ◽  
Author(s):  
Jin Huang ◽  
Shu Jiang ◽  
Xiaoqin Xu ◽  
Haishui Wu ◽  
Xiangcheng Zhu ◽  
...  
2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.


2002 ◽  
Vol 29 (4) ◽  
pp. 170-176
Author(s):  
I Sá-Correia ◽  
A M Fialho ◽  
P Videira ◽  
L M Moreira ◽  
A R Marques ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 491
Author(s):  
Kazuki Kano ◽  
Hiroaki Kitazawa ◽  
Keitaro Suzuki ◽  
Ani Widiastuti ◽  
Hiromitsu Odani ◽  
...  

Effects of corn steep liquor (organic fertilizer, OF) and conventional chemical fertilizer (CF) on the growth and yield of bok choy (Brassica rapa var. chinensis) in summer and autumn hydroponic growing systems were compared. When OF and CF were applied with the same amount of total nitrogen in summer cultivation, there was no significant difference between yields; however, the growth rate in OF was slower than in CF. When OF was applied with twice the amount of nitrogen in CF (OF2), bok choy growth and yield were significantly inhibited in summer cultivation, likely owing to dissolved oxygen deficiency and different rates of nitrification and nitrogen absorbance by the plant root. Although the contents of potassium, calcium, and magnesium in bok choy showed no difference among the three treatments in both cultivation seasons, the carbon/nitrogen ratio tended to be higher in OF and OF2 than in CF. Lower nitric acid and higher ascorbic acid content was found in OF and OF2 than in CF. Overall, our results suggest that a comparable yield is expected by using the same nitrogen amount with a conventional recipe of chemical fertilization in autumn cultivation. However, further improvement of hydroponic management is needed in summer cultivation.


RSC Advances ◽  
2020 ◽  
Vol 10 (39) ◽  
pp. 23212-23220
Author(s):  
Jian Xu ◽  
Xiawei Liu ◽  
Jiaolong Huang ◽  
Manqi Huang ◽  
Tao Wang ◽  
...  

Schematic diagram of RDCWs system and proposed mechanisms for nitrate removal.


2015 ◽  
Vol 5 ◽  
pp. 46-54 ◽  
Author(s):  
Mélida del Pilar Anzola-Rojas ◽  
Samantha Gonçalves da Fonseca ◽  
Cynthia Canedo da Silva ◽  
Valeria Maia de Oliveira ◽  
Marcelo Zaiat

1972 ◽  
Vol 50 (11) ◽  
pp. 2097-2102 ◽  
Author(s):  
R. Hall ◽  
H. Ly

The development of microsclerotia of Verticillium dahliae from a few swollen hyaline cells on a hypha to a multicellular, pigmented "mature" structure is described and illustrated. A method for quantitatively estimating the amount of pigmented microsclerotial material in pure cultures was developed to study quantitative relations between mycelial growth and production of microsclerotial material in media containing different concentrations of glucose. At low glucose concentrations (0.6 to 10 mg/ml) microsclerotial material continued to increase after total dry weight of the cultures had reached a maximum, suggesting conversion of hyaline to pigmented material. At high glucose concentrations (20 to 60 mg/ml) the patterns of increase in total dry weight, microsclerotial material, and hyaline material were similar over a 4-week incubation period. Maximum production of both pigmented and hyaline materials occurred at a glucose concentration of 30 mg/ml (carbon/nitrogen ratio of 50/1).


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