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The formation of acid mine drainage (AMD) is a common environmental problem in the mining industry. Its passive management through wetland construction has gained more consideration in recent years. However, the application in the field is constrained by the large area and relatively shallow depth. Indonesia has no passive technology to neutralize AMD in deep water. One solution is to apply a floating treatment wetland (FTW) system. Therefore, this study aimed to determine the ability of several hyperaccumulator plants, such as Melaleuca cajuputi, Nauclea orientalis, and Vetiveria zizanioides, to neutralize AMD using a floating system by conducting FTW trials. The method used was a Completely Randomized Design (CRD) with 3 treatments and control/without plants. Each treatment had 3 replications, resulting in 12 experimental units. The results showed that the FTW with or without plants could increase pH and decrease dissolved Mn by 75.31-90.74%. Heavy metals were chelated by organic matter, absorbed by plants, and deposited in the form of metal sulfides. The results also indicated that besides having a positive effect on pH and heavy metal reduction, the organic-based floating wetland increased biological oxygen demand (BOD) from 61.08-79.71%. [ABSTRACT FROM AUTHOR]

Background: Cajuputs candy (CC), an Indonesian functional food, utilizes the bioactivity of Melaleuca cajuputi essential oil (MCEO) to maintain oral cavity health. Synergistic interaction between Candida albicans and Streptococcus mutans is a crucial step in the pathogenesis of early childhood caries. Our recent study revealed several alternative MCEOs as the main flavors in CC. The capacity of CC to interfere with the fungus-bacterium relationship remains unknown. This study aimed to evaluate CC efficacy to impair biofilm formation by these dual cariogenic microbes. Methods: The inhibition capacity of CC against mixed-biofilm comprising C. albicans and S. mutans was assessed by quantitative (crystal violet assay, tetrazolium salt [MTT] assay, colony forming unit/mL counting, biofilm-related gene expression) and qualitative analysis (light microscopy and scanning electron microscopy). Result: Both biofilm-biomass and viable cells were significantly reduced in the presence of CC. Scanning electron microscopy imaging confirmed this inhibition capacity, demonstrating morphology alteration of C. albicans , along with reduced microcolonies of S. mutans in the biofilm mass. This finding was related to the transcription level of selected biofilm-associated genes, expressed either by C. albicans or S. mutans . Based on qPCR results, CC could interfere with the transition of C. albicans yeast form to the hyphal form, while it suppressed insoluble glucan production by S. mutans . G2 derived from Mojokerto MCEO showed the greatest inhibition activity on the relationship between these cross-kingdom oral microorganisms (p < 0.05). Conclusion: In general, all CC formulas showed biofilm inhibition capacity. Candy derived from Mojokerto MCEO showed the greatest capacity to maintain the commensal form of C. albicans and to inhibit extracellular polysaccharide production by S. mutans . Therefore, the development of dual-species biofilms can be impaired effectively by the CC tested., Competing Interests: Competing interests: IPB University is the patent holder for Cajuputs candy and CHW and BMB are named on the patent. However, the authors declare that they do not have any financial interest to disclose., (Copyright: © 2019 Septiana S et al.)