Abundance of Bacterial Colonies in Aquatic Ponds in Purwodadi Botanical Garden Pasuruan

The Purwodadi Botanical Garden plays a significant role in conserving Indonesia’s plant biodiversity, particularly dry lowland species. Among its collections are aquatic plants distributed across several ponds with varying abiotic conditions, such as physical and chemical parameters, which influence plant distribution. Additionally, biotic factors like bacteria serve as environmental bioindicators and contribute to the decomposition of organic matter. This study aimed to assess the abundance and morphological characteristics of bacterial colonies, and to examine the relationship between environmental parameters and bacterial abundance in selected ponds at the Purwodadi Botanical Garden. Observations and sampling were conducted on ten ponds, and bacterial growth was analyzed using the pour plate method. Colony density was expressed in colony-forming units per milliliter (CFU/mL). Results showed that bacterial colony densities ranged from 35 to 103 CFU/mL, with colonies exhibiting round or rhizoid shapes, white coloration, and smooth or wavy edges. Bacterial abundance was positively influenced by higher light intensity and near-neutral pH levels. These findings contribute to a better understanding of microbial-environment interactions and provide useful insights for the ecological management of aquatic plant habitats in the Purwodadi Botanical Garden