scholarly journals Bioprospecting for Novel Halophilic and Halotolerant Sources of Hydrolytic Enzymes in Brackish, Saline and Hypersaline Lakes of Romania

2020 ◽  
Vol 8 (12) ◽  
pp. 1903
Author(s):  
Robert Ruginescu ◽  
Ioana Gomoiu ◽  
Octavian Popescu ◽  
Roxana Cojoc ◽  
Simona Neagu ◽  
...  
Keyword(s):  
Hydrolytic Enzymes ◽  
Agar Plate ◽  
Halophilic Archaea ◽  
Hydrolytic Activity ◽  
Salt Tolerant ◽  
Genus Bacillus ◽  
Hydrolytic Activities ◽  
Extremely Halophilic Archaea ◽  
Biotechnological Processes ◽  
Microbial Isolates

Halophilic and halotolerant microorganisms represent promising sources of salt-tolerant enzymes that could be used in various biotechnological processes where high salt concentrations would otherwise inhibit enzymatic transformations. Considering the current need for more efficient biocatalysts, the present study aimed to explore the microbial diversity of five under- or uninvestigated salty lakes in Romania for novel sources of hydrolytic enzymes. Bacteria, archaea and fungi were obtained by culture-based approaches and screened for the production of six hydrolases (protease, lipase, amylase, cellulase, xylanase and pectinase) using agar plate-based assays. Moreover, the phylogeny of bacterial and archaeal isolates was studied through molecular methods. From a total of 244 microbial isolates, 182 (74.6%) were represented by bacteria, 22 (9%) by archaea, and 40 (16.4%) by fungi. While most bacteria synthesized protease and lipase, the most frequent hydrolase produced by fungi was pectinase. The archaeal isolates had limited hydrolytic activity, being able to produce only amylase and cellulase. Among the taxonomically identified isolates, the best hydrolytic activities were observed in halotolerant bacteria belonging to the genus Bacillus and in extremely halophilic archaea of the genera Haloterrigena and Halostagnicola. Therefore, the present study highlights that the investigated lakes harbor various promising species of microorganisms able to produce industrially valuable enzymes.

scholarly journals Isolation, Identification and Extracellular Enzymatic Activity of Culturable Extremely Halophilic Archaea and Bacteria of IncheBoroun Wetland

2016 ◽  
Vol 56 ◽  
pp. 40-51 ◽  
Author(s):  
Mehrnoosh Rasooli ◽  
Mohammad Ali Amoozegar ◽  
Abbas Akhavan Sepahy ◽  
Hamid Babavalian ◽  
Hamid Tebyanian
Keyword(s):  
Phylogenetic Analysis ◽  
Culture Media ◽  
Amylase Activity ◽  
Hydrolytic Enzymes ◽  
Halophilic Archaea ◽  
The North ◽  
Extremely Halophilic Archaea ◽  
North Of Iran ◽  
Physiological Tests ◽  
Culture Dependent

Extremely halophilic diversity of IncheBroun wetland located in the north of Iran was investigated by using culture-dependent methods. Sampling was carried out in May and September 2014. In each sampling 4 distinct regions of wetland were analyzed by using complex media like MGM, JCM168, MH1 and an alkaliphilic medium containing 23% salts. After incubation at 40°C, a total of 406 isolates and 2.1 × 106CFU/ml were obtained in culture media. Among them 361 isolates were obtained from MGM and 39 isolates from JCM 168, 3 isolates from MH1 and 3 isolates from the alkaliphilic media. Initial morphological, biochemical and physiological tests were performed. Production of 4 hydrolytic enzymes by 45 selected strains was assayed qualitatively. A total of 38, 19 and 6 strains were able to produce lipase, DNase and amylase activity. Protease activity was not observed among strains. As total 45 strains were selected randomly and phylogenetic analysis of 16S rRNA was performed for them. Among selected strains 40 isolated strians belonged to Haloarchaea and were belonged to the genera:Haloarcula(30%),Halorubrum(27.5%),Haloferax(17.5%),Halobellus(10%),Halogeometricum(5.2%),Halobacterium(2.6%),Halolamina(2.6%),Halorhabdus(2.6%) andHalostagnicola(2.6%).HaloarculaandHalorubrumwere the dominant populations. A total of 5 strains belonged to domain ofBacteriaand were similar to members ofRhodovibrio(40%),Pseudomonas(40%) andSalicola(20%).

scholarly journals Anaerobic hydrolysis of complex substrates in full-scale aerobic granular sludge: enzymatic activity determined in different sludge fractions

2021 ◽  
Author(s):  
Sara Toja Ortega ◽  
Mario Pronk ◽  
Merle K. de Kreuk
Keyword(s):  
Hydrolytic Enzymes ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Granular Sludge ◽  
Hydrolytic Activity ◽  
Full Scale ◽  
Aerobic Granular Sludge ◽  
Bulk Liquid ◽  
Granule Formation ◽  
Hydrolysis Of

Abstract Complex substrates, like proteins, carbohydrates, and lipids, are major components of domestic wastewater, and yet their degradation in biofilm-based wastewater treatment technologies, such as aerobic granular sludge (AGS), is not well understood. Hydrolysis is considered the rate-limiting step in the bioconversion of complex substrates, and as such, it will impact the utilization of a large wastewater COD (chemical oxygen demand) fraction by the biofilms or granules. To study the hydrolysis of complex substrates within these types of biomass, this paper investigates the anaerobic activity of major hydrolytic enzymes in the different sludge fractions of a full-scale AGS reactor. Chromogenic substrates were used under fully mixed anaerobic conditions to determine lipase, protease, α-glucosidase, and β-glucosidase activities in large granules (>1 mm in diameter), small granules (0.2–1 mm), flocculent sludge (0.045–0.2 mm), and bulk liquid. Furthermore, composition and hydrolytic activity of influent wastewater samples were determined. Our results showed an overcapacity of the sludge to hydrolyze wastewater soluble and colloidal polymeric substrates. The highest specific hydrolytic activity was associated with the flocculent sludge fraction (1.5–7.5 times that of large and smaller granules), in agreement with its large available surface area. However, the biomass in the full-scale reactor consisted of 84% large granules, making the large granules account for 55–68% of the total hydrolytic activity potential in the reactor. These observations shine a new light on the contribution of large granules to the conversion of polymeric COD and suggest that large granules can hydrolyze a significant amount of this influent fraction. The anaerobic removal of polymeric soluble and colloidal substrates could clarify the stable granule formation that is observed in full-scale installations, even when those are fed with complex wastewaters. Key points • Large and small granules contain >70% of the hydrolysis potential in an AGS reactor. • Flocculent sludge has high hydrolytic activity but constitutes <10% VS in AGS. • AGS has an overcapacity to hydrolyze complex substrates in domestic wastewater. Graphical abstract

Mutations affecting the activity of the cyclodextrin glucanotransferase of Paenibacillus pabuli US132: insights into the low hydrolytic activity of cyclodextrin glucanotransferases

Biologia ◽  
2012 ◽  
Vol 67 (4) ◽  
Author(s):  
Sonia Jemli ◽  
Mamdouh Ben-Ali ◽  
Hajer Ben-Hlima ◽  
Bassem Khemakhem ◽  
Samir Bejar
Keyword(s):  
Hydrolytic Activity ◽  
Influential Factor ◽  
Rational Approach ◽  
Cyclodextrin Glucanotransferase ◽  
Hydrolytic Activities ◽  
Maltogenic Amylase ◽  
Structural Barrier ◽  
First Time

AbstractThe cyclodextrin glucanotransferase from Paenibacillus pabuli US132 (US132 CGTase) was engineered using a rational approach in an attempt to provide it with anti-staling properties comparable to those of the commercial maltogenic amylase (Novamyl). The study aimed to concurrently decrease the cyclization activity and increase the hydrolytic activity of US132 CGTase. A five-residue loop (PAGFS) was inserted, alone or with the substitution of essential residues for cyclization (G180, L194 and Y195), mimicking the case of Novamyl. The findings indicate that, unlike the case of the CGTase of Thermoanerobacterium thermosulfurigenes strain EM1 whose initial high hydrolytic activity was exceptional, these mutations completely abolished the cyclization and hydrolytic activities of the US132 CGTase. This suggests that those mutations are not able to convert conventional CGTases, whose hydrolytic activities are very weak, into hydrolases. Accordingly, and for the first time, a structural barrier at subsite −3 was advanced as an influential factor which might explain the low hydrolytic activity of conventional CGTases.

scholarly journals Prospects of using extremely low doses of physical factors impact in food biotechnology

2018 ◽  
Vol 6 (2) ◽  
pp. 305-313 ◽  
Author(s):  
Tatiana Danilchuk ◽  
Tatiana Danilchuk ◽  
Vera Ganina ◽  
Vera Ganina
Keyword(s):  
Hydrolytic Enzymes ◽  
Physical Factor ◽  
Maximum Activity ◽  
Physical Factors ◽  
Experimental Sample ◽  
Low Doses ◽  
Resource Saving ◽  
Food Biotechnology ◽  
Low Intensity ◽  
Biotechnological Processes

The paper deals with urgent issues of development of resource-saving methods of biotechnological processes intensification. The main purpose of the work is to show the efficiency of using extremely low doses of physical factors impact in food biotechnology. Acoustic and electric treatment was in various modes. Impact capacity did not exceed 10-4 W/kg. The duration of exposure ranged from 5 to 15 min. Barley grains enzymes and lactic acid microorganisms were subjected to treatment. Impact of vibration as a physical factor, its frequency is considered as a priority in controlling growth and biochemical processes in biological objects. Impact frequency in the range of 50–10000 Hz influences the activity of hydrolytic enzymes in bimodal way. It is presented in the article. The coincidence of the frequency ranges of the maximum activity of enzymes in the model reactions with the ones in the grain of barley under the treatment of alternating current and sound is noted. Improvement of all indexes of germinating barley and improvement of the quality of the finished malt were observed in these ranges. Low-intensity acoustic treatment at a frequency of 2000 Hz contributed to an increase in β-galactosidase activity of the CT-95 Str. thermophilus strain. Selected ST-95 Str. thermophilus strain was used in the starter composition for the experimental sample production of fermented melted milk. The fermentation process intensification was observed. The lactose content of this product is 30% less in comparison with the feedstock. The use of traditional starter without a selected strain can reduce the lactose content by an average of 7.5%. The results of biotechnological processes modification by means of the treatment of enzymes and extremely low doses of physical factors impact used in meat technologies are observed. Thus, the prospects of using low-intensity physical effects of vibration in the development of innovative food technologies are substantiated. It is also promising to use these technologies in making absolutely new food products with different qualities.

scholarly journals In vitro activities of Traganum nudatum and Mentha pulegium extracts combined with amphotericin B against Candida albicans in production of hydrolytic enzymes

2020 ◽  
Author(s):  
Ikram Tefiani ◽  
Sidi Mohammed Lahbib Seddiki ◽  
Moustafa Yassine Mahdad
Keyword(s):  
Candida Albicans ◽  
Minimum Inhibitory Concentration ◽  
Amphotericin B ◽  
Inhibitory Concentration ◽  
Culture Media ◽  
Hydrolytic Enzymes ◽  
Normal Flora ◽  
Mentha Pulegium ◽  
Hydrolytic Activities

Background and Purpose: Candida albicans is an important microorganism in the normal flora of a healthy subject; however, it has an expedient pathogenic character that induces hydrolytic virulence. Regarding this, the present study aimed to find an in vitro alternative that could reduce the virulence of this yeast. Materials and Methods: For the purpose of the study, the effect of amphotericin B (AmB) combined with the extract of Traganum nudatum (E1) or Mentha pulegium (E2) was evaluated against the hydrolytic activities of esterase, protease, and phospholipase. This effect was determined by calculating the minimum inhibitory concentration (MIC), used to adjust the extract/AmB mixtures in culture media. Results: The evaluated Pz values, which corresponded to the different enzymatic activities, showed a decrease in the hydrolytic activities of C. albicans strains after the addition of E1/AmB and E2/AmB combinations at descending concentrations (lower than the obtained MICs). Conclusion: Based on the findings, it would be possible to reduce the pathogenesis of this species without destabilizing the balance of the flora.

scholarly journals Exploring the hydrolytic potential of cultured halophilic bacteria isolated from the Atacama Desert

2019 ◽  
Vol 366 (17) ◽  
Author(s):  
Robert Ruginescu ◽  
Cristina Purcărea ◽  
Cristina Dorador ◽  
Paris Lavin ◽  
Roxana Cojoc ◽  
...  
Keyword(s):  
Halophilic Bacteria ◽  
Agar Plate ◽  
Atacama Desert ◽  
Industrial Processes ◽  
Biotechnological Applications ◽  
Bacterial Isolates ◽  
Salt Tolerant ◽  
Essential Step ◽  
Extremophilic Microorganisms ◽  
Biological Sources

ABSTRACT Considering that most industrial processes are carried out under harsh physicochemical conditions, which would inactivate enzymes from commonly isolated mesophilic organisms, current studies are geared toward the identification of extremophilic microorganisms producing enzymes resistant to extreme salt concentrations, temperature and pH. Among the extremophiles, halophilic microorganisms are an important source of salt-tolerant enzymes that can be used in varying biotechnological applications. In this context, the aim of the present work was to isolate and identify halophiles producing hydrolases from the Atacama Desert, one of the harshest environments on Earth. Isolates were recovered from halite samples and screened for the presence of seven different hydrolase activities (amylase, caseinase, gelatinase, lipase, pectinase, cellulase and inulinase) using agar plate-based assays. From a total of 23 halophilic bacterial isolates, most showed lipolytic (19 strains) and pectinolytic (11 strains) activities. The molecular identification of eight selected isolates showed a strong similarity to members of the Halomonas and Idiomarina genera. Therefore, the present study represents a preliminary, but essential, step to identify novel biological sources of extremozymes in an environment once thought to be devoid of life.

scholarly journals Methylomes of Two Extremely Halophilic Archaea Species, Haloarcula marismortui and Haloferax mediterranei

2019 ◽  
Vol 8 (27) ◽  
Author(s):  
Shiladitya DasSarma ◽  
Alexey Fomenkov ◽  
Satyajit L. DasSarma ◽  
Tamas Vincze ◽  
Priya DasSarma ◽  
...  
Keyword(s):  
Single Molecule ◽  
Gene Annotation ◽  
Halophilic Archaea ◽  
Restriction Enzymes ◽  
Haloferax Mediterranei ◽  
Haloarcula Marismortui ◽  
Content Type ◽  
Extremely Halophilic Archaea ◽  
Large Plasmids ◽  
Methyl Cytosine

ABSTRACT The genomes of two extremely halophilic Archaea species, Haloarcula marismortui and Haloferax mediterranei, were sequenced using single-molecule real-time sequencing. The ∼4-Mbp genomes are GC rich with multiple large plasmids and two 4-methyl-cytosine patterns. Methyl transferases were incorporated into the Restriction Enzymes Database (REBASE), and gene annotation was incorporated into the Haloarchaeal Genomes Database (HaloWeb).

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