Biosurfactant production and growth kinetics studies of the waste canola oil-degrading bacterium Rhodococcus erythropolis AQ5-07 from Antarctica

first_imgWith the progressive increase in human activities in the Antarctic region, the possibility of domestic oil spillage also increases. Developing means for the removal of oils, such as canola oil, from the environment and waste “grey” water using biological approaches is therefore desirable, since the thermal process of oil degradation is expensive and ineffective. Thus, in this study an indigenous cold-adapted Antarctic soil bacterium, Rhodococcus erythropolis strain AQ5-07, was screened for biosurfactant production ability using the multiple approaches of blood haemolysis, surface tension, emulsification index, oil spreading, drop collapse and “MATH” assay for cellular hydrophobicity. The growth kinetics of the bacterium containing different canola oil concentration was studied. The strain showed β-haemolysis on blood agar with a high emulsification index and low surface tension value of 91.5% and 25.14 mN/m, respectively. Of the models tested, the Haldane model provided the best description of the growth kinetics, although several models were similar in performance. Parameters obtained from the modelling were the maximum specific growth rate (qmax), concentration of substrate at the half maximum specific growth rate, Ks% (v/v) and the inhibition constant Ki% (v/v), with values of 0.142 h−1, 7.743% (v/v) and 0.399% (v/v), respectively. These biological coefficients are useful in predicting growth conditions for batch studies, and also relevant to “in field” bioremediation strategies where the concentration of oil might need to be diluted to non-toxic levels prior to remediation. Biosurfactants can also have application in enhanced oil recovery (EOR) under different environmental conditions.last_img read more

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Caribbean boxing officials gather for ‘critical’ meeting today

first_img… AIBA turmoil to be topical discussionCARIBBEAN boxing representatives will gather today at the National Resource Centre in Georgetown, for what president of the Guyana Boxing Association (GBA) Steve Ninvalle is calling a ‘critical’ meeting, especially with the sport’s global body, International Boxing Association (AIBA) in chaos.“The meeting will be looking at the Caribbean’s approach to AIBA, especially with all that’s going on,” Ninvalle highlighted yesterday.AIBA’s Taiwanese president Ching-kuo Wu was suspended by a disciplinary commission. The organisation has been riven with in-fighting for months, with Wu pitted against most of the executive committee, who failed to remove him through a vote of no-confidence tabled in July.AIBA said that the 70-year-old was served with a provisional and immediate suspension from duties pending the conclusion of a complaint against him.It said the complaint was made by 11 AIBA executive committee members on October 1 who alleged that Wu had “violated and continues to violate various provisions of AIBA’s Statutes and Codes” and demanded his suspension.William Louis-Marie, AIBA’s Executive Director was initially scheduled to attend today’s meeting, but Ninvalle said that the latest development at the sport’s governing body impeded his (Louis-Marie) attendance.The America Boxing Confederation (AMBC) will be represented by its Executive Directors Hernan Salvo and Avasldo Bisbal and, together with the eight representatives of the Caribbean, matters of importance will be addressed.“The AMBC actually wanted this meeting to be rescheduled, but I can’t do that, because, what’s happening in AIBA right now will affect us and we need to meet as a collective and figure out the way forward. We can’t suspend the meeting again, not once I’m playing any part in it and we will move on,” Ninvalle said.Ninvalle pointed out that the turmoil in AIBA could affect December’s Caribbean Championships in St Lucia since they (AIBA) had offered US$25 000 to help the host offset expenses.“That support is huge because it’s the first time AIBA offered any financial support. Usually, we go through it alone and it’s very difficult, and that support would really help in a major way,” Ninvalle commented.Ninvalle is an Executive Director at AIBA and was recently named on the organisation’s Executive Committee Bureau but at today’s meeting, Ninvalle said, “I wear many hats, I know, but today, I’m GBA president. This meeting is very critical in terms of moving the sport forward especially with all that’s happening at AIBA.”last_img read more

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