ABSTRACT
Excessive use of antibiotics has led to an increase of pathogenic bacteria with multiple antibiotic resistance. Hypersaline and hyperthermal environments promote the development of several microorganisms that can potentially act as immunostimulants. Thus, the aim of this study was bioprospecting marine bacteria from these environments using mouse leukocytes as a cell model for assess immunostimulatory activity. Samples were taken from two evaporation ponds with 4 and 8% salinity (p/v) in a marine solar saltern (MSS) at Laguna Ojo de Liebre, Guerrero Negro and a shallow hydrothermal vent (SHV), Bahía Concepción under a mangrove forest both off Baja California Sur, México. From total number of isolates (N = 340), 267 were obtained from the MSS and 73 from the SHV. The 10 isolates that induced nitric oxide (NO) production in mouse splenocytes were identified using the 16S rRNA gene, of which Halomonas elongata, Halomonas sp., Pseudoalteromonas ruthenica, Bacillus subtilis and three Bacillus strains were isolated from the MSS ponds at 8% salinity and three Marinobacter lutaoensis strains from the SHV. Most of the selected bacteria were not cytotoxic for mouse splenocytes and enhanced phagocytic respiratory burst and antioxidant enzyme activities compared to the control immunostimulant (lipopolysaccharide from Escherichia coli). Selected bacteria from 8% salinity ponds in the MSS in Guerrero Negro had immunostimulant activity in vitro in mouse splenocytes. In conclusion, Bacillus subtilis SA4 220, Bacillus sp. SA4 62A, P. ruthenica SA4 40 as well as Halomonas sp. SA4 207 and Halomonas elongata SA8 44 increased several immunological parameters. Further research is needed to evaluate their potential application in preclinical models to fight against infectious diseases. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-022-01002-3.
ABSTRACT
Copper-zinc superoxide dismutase (SODC) is a cytosolic enzyme which catalyses the dismutation of the superoxide radical. Due to its physiological importance, the encoding genes have been cloned from several species of higher eukaryotes. However, genes from moulds and yeast have not been studied extensively. In this paper, the encoding region of this gene (sod1) has been cloned from several strains of marine yeast belonging to the genus Debaryomyces (dvv sod1, dvy sod1 and dh sod1-61) through genomic DNA-PCR amplification. Fragments of 480-486 nucleotides were obtained, which contain information for products of 153-156 amino acids with calculated molecular masses of 15.8-16.6 kDa. The deduced amino acid sequence shows that D. vanrijiae enzymes present three additional amino acids not closely related to the active site conformation. In addition, in D. vanrijiae var. vanrijiae (strain 020), one histidine residue is apparently replaced by a proline; the incidence and function of other aromatic or heterocyclic amino acids is discussed. Homology and phylogenetic trees were constructed from amino-acid sequence multi-alignment analyses; the interrelationships among fungi are discussed. The sod-1 sequences reported in this paper were deposited in the public data library of the NCBI under Accession Nos AF301019, AF327449 and AF327448.
