Cyanobacteria are one of the most important groups of photoautotrophic organisms, contributing to carbon and nitrogen fixation in mangroves worldwide. They also play an important role in soil retention and stabilisation and contribute to high plant productivity through their secretion of plant growth-promoting substances. However, their diversity and distribution in Malaysian mangrove ecosystems have yet to be studied in detail, despite Malaysia hosting a significant element of remaining mangroves globally. In a floristic survey conducted in Penang, peninsular Malaysia, 33 morphospecies of periphytic cyanobacteria were identified and described for the first time from a mangrove ecosystem in Malaysia. Sixteen genera, comprising Aphanocapsa, Chroococcus, Chroococcidiopsis, Cyanobacterium, Desmonostoc, Geitlerinema, Leptolyngbya, Lyngbya, Microcystis, Myxosarcina, Oscillatoria, Phormidium, Pseudanabaena, Spirulina, Trichocoleus and Xenococcus, were obtained from field material growing on diverse natural and artificial substrata. Oscillatoriales was the dominant order with Phormidium the dominant genus at nine of the 15 sampling sites examined. Three of the morphospecies, Aphanocapsa cf. concharum, Xenococcus cf. pallidus and Oscillatoria pseudocurviceps, are rare and poorly known morphospecies worldwide. Chroococcus minutus, Phormidium uncinatum, P. amphigranulata, and some species of Oscillatoriales are considered as pollution indicator species. This study provides important baseline information for further investigation of the cyanobacterial microflora present in other mangrove areas around Malaysia. A complete checklist will enhance understanding of their ecological role and the potential for benefits arising from useful secondary metabolites or threats via toxin production to the ecosystem.
Cyanobacteria adalah salah satu kumpulan organisma fotoautotropik yang paling penting yang menyumbang kepada penetapan karbon dan nitrogen dalam paya bakau di seluruh dunia. Mereka juga memainkan peranan yang penting dalam pengekalan dan penstabilan tanah dan menyumbang kepada produktiviti tumbuhan yang tinggi melalui rembesan bahan penggalak pertumbuhan tumbuhan. Walau bagaimanapun, kepelbagaian dan taburannya dalam ekosistem paya bakau Malaysia masih belum dikaji secara terperinci, walaupun Malaysia menjadi tuan rumah elemen penting bagi baki bakau di peringkat global. Dalam tinjauan floristik yang dijalankan di Pulau Pinang, Semenanjung Malaysia, 33 morfospesies cyanobacteria perifit telah dikenal pasti dan diterangkan buat kali pertama daripada ekosistem bakau di Malaysia. Sebanyak 16 genera, yang terdiri daripada Aphanocapsa, Chroococcus, Chroococcidiopsis, Cyanobacterium, Desmonostoc, Geitlerinema, Leptolyngbya, Lyngbya, Microcystis, Myxosarcina, Oscillatoria, Phormidium, Pseudanabaena, Spirulina, Trichocoleus dan Xenococcus, yang tumbuh secara semula jadi diperolehi daripada pelbagai bahan tumbuh-tumbuhan semula jadi dan tiruan. Oscillatoriales ialah susunan dominan dengan Phormidium merupakan genus dominan di 9 daripada 15 tapak persampelan yang diperiksa. Tiga daripada morfospesies, Aphanocapsa cf. concharum, Xenococcus cf. pallidus dan Oscillatoria pseudocurviceps, adalah morfospesies yang jarang dan kurang dikenali di seluruh dunia. Chroococcus minutus, Phormidium uncinatum, P. amphigranulata, dan beberapa spesies Oscillatoriales dianggap sebagai spesies penunjuk pencemaran. Kajian ini menyediakan maklumat asas yang penting untuk penyiasatan lanjut tentang mikroflora cyanobacterial yang terdapat di kawasan bakau lain di sekitar Malaysia. Senarai semak yang lengkap akan meningkatkan pemahaman tentang peranan ekologi mereka dan potensi manfaat yang timbul daripada metabolit sekunder yang berguna atau ancaman melalui pengeluaran toksin kepada ekosistem.