The use of molecular diagnostic techniques for bioprospecting and microbial diversity study purposes has gained more attention thanks to their functionality, low cost and quick results. In this context, ten degenerate primers were designed for the amplification of polyhydroxyalkanoate synthase (phaC) gene, which is involved in the production of polyhydroxyalkanoate (PHA)—a biodegradable, renewable biopolymer. Primers were designed based on multiple alignments of phaC gene sequences from 218 species that have their genomes already analyzed and deposited at Biocyc databank. The combination of oligos phaCF3/phaCR1 allowed the amplification of the expected product (PHA synthases families types I and IV) from reference organisms used as positive control (PHA producer). The method was also tested in a multiplex system with two combinations of initiators, using 16 colonies of marine bacteria (pre-characterized for PHA production) as a DNA template. All amplicon positive organisms (n = 9) were also PHA producers, thus no false positives were observed. Amplified DNA was sequenced (n = 4), allowing for the confirmation of the phaC gene identity as well its diversity among marine bacteria. Primers were also tested for screening purposes using 37 colonies from six different environments. Almost 30% of the organisms presented the target amplicon. Thus, the proposed primers are an efficient tool for screening bacteria with potential for the production of PHA as well to study PHA genetic diversity.

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Three acidophilic bacteria were isolated from water and sediment samples collected at a coal mining-impacted river, Rio Sangão, located in the city of Criciúma, Santa Catarina state, in southern Brazil. These microorganisms were isolated in acid media and were phylogenetic related to the species Acidiphilium cryptum by its 16S rRNA gene sequences, although they differ from this species in the assimilation of some carbon sources. The optimum and the maximum pH for growth of all strains were nearly 3.0 and 5.0-6.0, respectively. Two of the strains were slightly more acidophilic, with the minimum pH for growth of 2.0. All strains also tolerate the four tested metals (Ni, Zn, Cu and Se) at variable concentrations, with LAMA 1486 being the most metal-resistant strain. These bacteria may belong to different ecotypes of A. cryptum, or even represent new species in the genus. Besides they bear characteristics that make them useful in the development of bioremediation process, for the treatment of sites contaminated with multiple toxic metals, including coal mining drainage.