Lin Johnson, Madida Bafana B
School of Life Sciences, University of KwaZulu-Natal Westville, Private Bag X54001, Durban, 4000, South Africa.
J Basic Microbiol. 2015 Oct;55(10):1168-78. doi: 10.1002/jobm.201400886. Epub 2015 Apr 1.
The biodeterioration of metals have detrimental effects on the environment with economic implications. The deterioration of metals is of great concern to industry. In this study, mild steel coupons which were immersed in a medium containing Gram-positive Bacillus spp. and different nutrient sources were compared with the control in sterile deionized water. The weight loss of the coupons in the presence of Bacillus spp. alone was lower than the control and was further reduced when additional carbon sources, especially fructose, were added. The level of metal corrosion was significantly increased in the presence of nitrate with or without bacteria. There was a significant strong correlation between the weight loss and biofilm level (r = 0.64; p < 0.05). The addition of nitrate and Bacillus spp. produced more biofilms on the coupons and resulted in greater weight loss compared to that with Bacillus spp. only under the same conditions. However, Bacillus spp. enriched with carbon sources formed less biofilms and results in lower weight loss compared to that with Bacillus spp. only. The production of biofilm by Bacillus spp. influences the level of metal corrosion under different environmental conditions, thereby, supporting the development of a preventive strategy against corrosion.
金属的生物劣化对环境具有有害影响并涉及经济问题。金属的劣化是工业界极为关注的问题。在本研究中，将浸泡在含有革兰氏阳性芽孢杆菌属和不同营养源的介质中的低碳钢试片与无菌去离子水中的对照进行比较。仅在有芽孢杆菌属存在时试片的重量损失低于对照，并且当添加额外的碳源，尤其是果糖时，重量损失进一步降低。在有或没有细菌存在的情况下，硝酸盐的存在会显著增加金属腐蚀程度。重量损失与生物膜水平之间存在显著的强相关性（r = 0.64；p < 0.05）。与仅在相同条件下有芽孢杆菌属的情况相比，添加硝酸盐和芽孢杆菌属会在试片上产生更多生物膜并导致更大的重量损失。然而，与仅含芽孢杆菌属的情况相比，富含碳源的芽孢杆菌属形成的生物膜更少，重量损失更低。芽孢杆菌属生物膜的产生会影响不同环境条件下的金属腐蚀程度，从而为制定防腐蚀策略提供支持。
