Exploratory study on the genus diversity of tropical paludi-microalgae as a potential source of human nutrition and other products

Population growth and limited availability of agricultural land have created immense pressure for accessible food and nutritional supplements in Indonesia. To establish new food sources that will be sustainable in the long term, various government programmes have opened up land for agriculture in the peatlands of Central Kalimantan. However, the establishment of both large-scale plantations and community-based agriculture has required drainage of the peatlands leading to a decline in the habitat along with increased greenhouse gas emissions and incidence of peatland fires. The option of rewetting and adopting wetland agriculture (paludiculture) in these areas could significantly improve the preservation of both terrestrial carbon stocks and the native flora and fauna. Cultivating microalgae as part of paludiculture could provide additional resources including food for both humans and aquatic animals, benefitting agriculture and fisheries in the future. This preliminary study aims to identify microalgae genera in the tropical peat swamp waters of Central Kalimantan, and in particular to determine which of the microalgae present may have potential as sources of human nutrition as well as for other uses. Peat water samples were obtained from three distinct locations in Palangka Raya City. Specimens were identified using techniques based on morphological characteristics observed by photomicrography, and the nutritional potential of each genus was determined by literature review. The analysis revealed paludi-microalgae belonging to a total of 17 genera, two from Class Bacillariophyceae (Pinnularia, Navicula), two from Class Chlorophyceae (Pandorina, Scenedesmus), three from Class Cyanobacteria (Microcystis, Anabaena, Oscillatoria), four from Class Euglenophyceae (Euglena, Trachelomonas, Lepocinclis, Phacus) and six from Class Zygnematophyceae (Closterium, Cosmarium, Euastrum, Micrasterias, Spirogyra, Pleurotaenium). The highest number of microalgae genera was found in peat swamp ponds in Palangka Raya City Forest, which contributed 95 % of all genera obtained. Literature review revealed that several of these genera such as Spirogyra, Navicula and Euglena have high potential as food sources with significant nutritional properties, containing carbohydrates, proteins, lipids, fats, minerals and a range of vitamins. Various other useful properties were also identified.