Abstract

Microalgae are unicellular microorganisms with unique features and can be used as indicators for air pollutants. Microalgae have been found to withstand the negative effects of air pollutants. This study examined the relationship between the levels of carbon monoxide (CO) and the density of microalgal cells in different areas in Peninsular Malaysia, which has a hot and humid climate throughout the year. The influence of CO on the composition of microalgal species was also investigated. Microalgae samples were collected from four selected areas, chosen based on average CO readings for 2015 in the pattern of increasing values (low, medium, high) – Jerantut (low), Banting (medium), Kuala Lumpur (medium) and Petaling Jaya (high). The study found that Desmococcus olivaceus was the most widespread species found in the study areas whereas Trebouxia arboricola was the most dominant species. Trentepohlia rigidula, Coccomyxa confluens, Keratococcus bicaudatus, and Klebsormidium flaccidum can be categorised as non-tolerant to high levels of CO as they were only found in the area with low levels of CO, Jerantut. The study also showed that there was a perfect positive correlation between the CO levels and the number of microalgal cells. Data from the Jaccard Similarity Index indicates a low similarity in species composition between Jerantut and Banting, Kuala Lumpur and Petaling Jaya with Jaccard coefficients of 0.2857, 0.1250, and 0.1250, respectively. The outcomes from this study provide useful data in understanding the relationship of CO on microalgae cell density together with the composition of species and suggest the use of epiphytic microalgae as ecological indicators for air pollution.

摘要

微藻是具有独特特征的单细胞微生物，可作为空气污染物的指标。已经发现微藻可以抵抗空气污染物的负面影响。这项研究探讨了全年气候炎热潮湿的马来西亚半岛不同地区的一氧化碳 (CO) 水平与微藻细胞密度之间的关系。还研究了 CO 对微藻物种组成的影响。微藻样本是从四个选定区域收集的，这些区域是根据 2015 年的平均二氧化碳读数以递增值（低、中、高）的模式选择的——而连突（低）、万津（中）、吉隆坡（中）和八打灵再也（高的）。研究发现，Desmococcus olivaceus是研究区域发现的最广泛的物种，而Trebouxia arboricola是最主要的物种。Trentepohlia hardula、Coccomyxa confluens、Keratococcus bicaudatus和Klebsormidium flaccidum可以归类为对高浓度 CO 不耐受，因为它们仅在低浓度 CO 的地区发现，即连突。该研究还表明，CO 水平与微藻细胞数量之间存在完美的正相关关系。Jaccard 相似度指数的数据表明，Jaccard 系数分别为 0.2857、0.1250 和 0.1250 的而连突和万津、吉隆坡和八打灵再也之间的物种组成相似性较低。这项研究的结果为了解 CO 与微藻细胞密度以及物种组成的关系提供了有用的数据，并建议使用附生微藻作为空气污染的生态指标。