Bacteria as Potential Indicators of Heavy Metal Contamination in a Tropical Mangrove and the Implications on Environmental and Human Health

Abstract

Heavy metal (HM) exposure has been associated with human health diseases like cancer, kidney and liver damage, neurological disorders, motor skills, low bone density and learning problems. With the beginning of the industrialization, the heavy metals in high concentration contribute to putting on the risk the humans in the vicinity. Our study site is located in Cataño, Puerto Rico. This is a highly industrialized area. It is surrounded by a recreational park, a rum distillery, two thermoelectric factories, and was impacted by CAPECO (oil refinery) explosion in 2009. Las Cucharillas marsh is part of The San Juan Bay Estuary System, considered as a critical wildlife area. The mangrove marsh has three of the four mangrove species found in PR Laguncularia racemosa, Avicennia germinans and Rhizophora mangle. This study was aimed at seven different heavy metals: Arsenic (As), Cadmium (Cd), Chromium (Cr), Lead (Pb), Zinc (Zn), Mercury (Hg) and Copper (Cu). These metals at high concentrations are of human health concern due to their toxicity, persistence, bioaccumulative and bio magnification potentials. Contamination of surface sediments with HM affects the food chain, starting with marine organisms up to humans. The people who live near the contaminated area and the local fishermen are at high risk of exposure. Studies reveal that certain microorganisms can resist the toxicity of heavy metals even at high concentrations. Our study pretends to exploit the sensitive nature of some bacteria to HM and use them as bioindicators. The objective of this research is to assess the bacterial community on the mangrove marsh, identify these bacteria and correlate bacterial species with the type and concentration of the metals found on the site. Our preliminary results with the BIOLOG® identification were five bacteria that are: Carnobacterium inhibens, Cupriavidus gilardii, Enterococcus maloduratus, Microbacterium flavescens and Ralstonia pickettii. This study will continue with an assessment of the exposure of different concentrations of heavy metals to our identified bacteria and underlying the mechanisms of degradation, magnification and or bioconcentration of these heavy metals.

Comparative Genomics Reveals a Well-Conserved Intrinsic Resistome in the Emerging Multidrug-Resistant Pathogen Cupriavidus gilardii

“…Since then, C. gilardii has been isolated from multiple ecological niches, including untreated drinking water (5), urban pond water (6), agricultural soil (7), soil contaminated with heavy metals (8), soil containing natural asphalt (9), plants (10), and human clinical samples (11–17). At the environmental and biotechnological levels, this organism has gained attention because of its potential role as an indicator of heavy metal contamination (8), as well as its ability to degrade herbicides (7) and other toxic hydrocarbons, such as naphthenic acids (9).…”

Lead induced structural and functional damage and microbiota dysbiosis in the intestine of crucian carp (Carassius auratus)

“…Pb is widely present in the atmosphere, soil, and water and is a major pollutant in environmental monitoring and pollution control, with high toxicity to environmental organisms (Malik and Ahmad, 2002 ; Cruz et al, 2006 ; Melanie et al, 2015 ; Behera et al, 2021 ; Rout et al, 2022b ). It can change the body function by breaking the intestinal wall barrier, destroying the intestinal structure, and changing the expression levels of some important genes in fish (Xia et al, 2018 ; Shi et al, 2020 ).…”

Nanobiotechnology: Nature-inspired silver nanoparticles towards green synthesis

“…As a consequence, various marine organisms have been extensively studied in relation to the biosynthesis of AgNPs. Elkomyc 88 recently reported the synthesis of small-size AgNPs (1.83 nm – 26.15 nm) utilising cyanobacterium Phormidium formosum with bactericidal activity against various Gram-positive and Gram-negative bacteria. Biosynthesised AgNPs have also been reported to have potent antifungal activity against Candida albicans .…”