Extracellular hydrolytic enzyme production by proteolytic bacteria from the Antarctic

Abstract

Cold−adapted marine bacteria producing extracellular hydrolytic enzymes are important for their industrial application and play a key role in degradation of particulate or− ganic matter in their natural environment. In this work, members of a previously−obtained protease−producing bacterial collection isolated from different marine sources from Potter Cove (King George Island, South Shetlands) were taxonomically identified and screened for their ability to produce other economically relevant enzymes. Eighty−eight proteolytic bacterial isolates were grouped into 25 phylotypes based on their Amplified Ribosomal DNA Restriction Analysis profiles. The sequencing of the 16S rRNA genes from represen− tative isolates of the phylotypes showed that the predominant culturable protease−producing bacteria belonged to the class Gammaproteobacteria and were affiliated to the genera Pseu− domonas, Shewanella, Colwellia, and Pseudoalteromonas, the latter being the predominant group (64% of isolates). In addition, members of the classes Actinobacteria, Bacilli and Flavobacteria were found. Among the 88 isolates screened we detected producers of amylases (21), pectinases (67), cellulases (53), CM−cellulases (68), xylanases (55) and agarases (57). More than 85% of the isolates showed at least one of the extracellular enzy− matic activities tested, with some of them producing up to six extracellular enzymes. Our results confirmed that using selective conditions to isolate producers of one extracellular Pol. Polar Res. 34 (3): 253-267, 2013Res. 34 (3): 253-267, vol. 34, no. 3, pp. 253-267, 2013 doi: 10.2478/popore−2013−0014 Unauthenticated Download Date | 5/10/18 5:03 PM enzyme activity increases the probability of recovering bacteria that will also produce addi− tional extracellular enzymes. This finding establishes a starting point for future programs oriented to the prospecting for biomolecules in Antarctica.

Epimicrobiome Shifts With Bleaching Disease Progression in the Brown Seaweed Saccharina japonica

“…Moreover, the relative abundance of Pseudoalteromonas and Colwellia increased during the infection period. Previous studies have shown that Pseudoalteromonas and Colwellia seaweed isolates are capable of agar degradation (Sańchez Hinojosa et al, 2018), with some Pseudoalteromonas producing cold-adapted hydrolytic enzymes and exhibiting high agar-hydrolyzing activity, even at low temperatures (Hollants et al, 2013;Tropeano et al, 2013;Ivanova et al, 2014;Borchert et al, 2017;Sánchez Hinojosa et al, 2018). Other Pseudoalteromonas isolates have been identified as causative agents of disease of Laminaria japonica (Sawabe et al, 1998) and S. japonica (Zhang et al, 2022).…”

Characterization of a novel β-agarase from Antarctic macroalgae-associated bacteria metagenomic library and anti-inflammatory activity of the enzymatic hydrolysates

“…Recently, many agarases have been obtained from microorganisms from different environments, including sediment, seawater, and macroalgae. In the past 20 years, multiple studies have focused on macroalgae-associated bacteria and their production of polysaccharide-degrading enzymes (Tropeano et al, 2012(Tropeano et al, , 2013. However, there are few reports about polysaccharidedegrading enzymes obtained from the macroalgae-associated bacteria collected from Antarctica.…”

Diversity and plant growth-promoting potential of actinomycetes associated with the rhizosphere of Arnebia euchroma from Himachal Pradesh (India)

“…Hence, those actinomycetes which produce a wide spectrum of extracellular lytic ezymes are the ones with the greatest possibilities for successful adaptation to survive there. To thrive in these ecosystems, the actinomycetes should be able to uptake several substrates as nutrients (Tropeano et al, 2013) The perusal of data depicted in Table 5 reveal a significant difference (P<0.05) among actinomycetes in their ability to produce lytic enzymes extracellularly. In terms of chitinase -1 activity, the isolates NA6 and CA1 showed maximum (6.81 U ml ) protease activity (28.13 U ml ) was recorded for isolate NA7.…”