Paenibacillus alba nov., Isolated from Peat Soil

Enhancement of stability and activity of RSD amylase from Paenibacillus lactis OPSA3 for biotechnological applications by covalent immobilization on green silver nanoparticles

The key challenge to the biotechnological applications of amylases is achieving high activity and stability under extreme pH, temperature and often high levels of enzyme denaturants. This study immobilized a novel raw starch-digesting (RSD) amylase from Paenibacillus lactis OPSA3 on glutaraldehyde-activated silver nanoparticles. Effects of time, glutaraldehyde concentration, pH, temperature, and enzyme concentration on immobilization were studied, and the immobilized enzymes were characterized. pH 9.0 was optimum for the enzyme immobilization. The maximum immobilization efficiency of 82.23 ± 7.99 % was achieved at 25 °C for 120 min. After immobilization, the optimum pH and temperature changed from 9.0 to 11.0 and 60 to 70, respectively. Immobilization reduced the amylase's activation energy (KJ/mol) from the initial 58.862 to 45.449 following immobilization. The Km of the amylase decreased after immobilization, while the Vmax increased. The immobilized amylase showed significantly greater storage and thermal stability than the free amylase. At 80, enzyme half-life (min) and D value (min) increased from 12.33 to 179.11 and 40.94 to 594.98, respectively. The immobilized amylase (80-88 %) had more stability to the effects of the studied surfactants than the free enzyme. It also showed improved stability in the presence of commercial detergents compared to the free enzyme. The amylase's enhanced kinetic parameters and stability following successful immobilization on silver nanoparticles indicate its potential for application in the range of biotechnological processes where alkaline- and temperature-stable amylases are employed.

Detergent-stable amylase production by Paenibacillus lactis strain OPSA3 isolated from soil; optimization by response surface methodology

This study aimed to isolate thermostable, alkaliphilic, and detergent-tolerant amylase-producing bacteria. Pure isolates from environmental samples were screened on a starch-based medium (pH 11), and selected isolates were identified using cultural and molecular techniques. Product optimization studies were conducted, and secreted amylase was partially purified using 40% (w/v) saturation ammonium sulfate at 4 °C. The wash performance of concentrated amylase was analyzed. A novel isolate, Paenibacillus lactis OPSA3, was selected for further studies. The isolate produced amylase optimally when grown on banana peels and soybean extracts, which are agro-wastes. Optimization by Response surface Methodology resulted in a 2.1-fold increase in alkaliphilic amylase production. A 2.46-fold purification was achieved, with an enzyme activity yield of 79.53% and specific activity of 26.19 Umg^-1. Wash performance analysis using the amylase supplemented with boiled commercial detergent (kiln®) showed good cleaning efficiency. The amylase has the potential for application as a component of green detergent.

Paenibacillus foliorum sp. nov., Paenibacillus phytohabitans sp. nov., Paenibacillus plantarum sp. nov., Paenibacillus planticolens sp. nov., Paenibacillus phytorum sp. nov. and Paenibacillus germinis sp. nov., isolated from the Arabidopsis thaliana phyllosphere

Six endospore-forming, Gram-stain-positive or variable, motile, rod-shaped, aerobic or facultatively anaerobic bacteria with different MALDI-TOF mass spectra (MS) were isolated from the phyllosphere of Arabidopsis thaliana plants grown in plant chambers after inoculation of surface sterilized seeds with a top soil microbial cell suspension. They were identified as members of the genus Paenibacillus through comparison with a commercial MALDI-TOF MS database and comparative 16S rRNA gene sequencing. Their genome sequences comprised multiple biosynthetic gene clusters and suggested they have unexplored biotechnological potential. Analyses of average nucleotide identity values between these strains and the type strains of their nearest neighbour species demonstrated that they represented a novel Paenibacillus species each. A detailed phenotypic comparison yielded distinctive biochemical characteristics for each of these novel species. We therefore propose to classify that these isolates into six novel species within genus Paenibacillus, for which we propose the names Paenibacillus foliorum sp. nov., Paenibacillus phytohabitans sp. nov., Paenibacillus plantarum sp. nov., Paenibacillus planticolens sp. nov., Paenibacillus phytorum sp. nov. and Paenibacillus germinis sp. nov., with strains LMG 31456^T (=R-74617^T=CECT 30138^T), LMG 31459^T (=R-74621^T=CECT 30135^T), LMG 31461^T (=R-74618^T=CECT 30133^T), LMG 31457^T (=R-74619^T=CECT 30137^T), LMG 31458^T (=R-74620^T=CECT 30136^T) and LMG 31460^T (=R-74622^T=CECT 30134^T) as the type strains, respectively.

Gelidibacter flavus sp. nov., Isolated from Activated Sludge of Seawater Treatment System

A Gram-stain-negative bacterial strain designated Con4^T was isolated from activated sludge in a seawater treatment system. The strain was rod-shaped, motile, aerobic, and formed yellow-colored colonies on agar medium. Cells contained carotenoid pigments, but flexirubin-type pigments were absent. Based on 16S rRNA gene sequence analysis, the strain was assigned to the genus Gelidibacter. Optimum growth occurred at 20 °C, pH 7.0, and 1-2% (w/v) NaCl. Prominent fatty acid types were iso-C_15:0, anteiso-C_15:0, and iso-C_16:0 3OH. Diphosphatidylglycerol and phosphatidylethanolamine were present as the major polar lipids. MK-6 was present as major menaquinone. Strain Con4^T showed the highest sequence similarity with Gelidibacter mesophilus KCTC 12106^T (96.5%), Gelidibacter gilvus IC158^T (96.4%), and Gelidibacter algens ACAM 536^T (95.8%). The G+C mol% contents of the strain Con4^T were 37.7%. Distinct morphological, physiological, and genotypic differences from the previously described taxa support the classification of strain Con4^T as a representative of a novel species in the genus Gelidibacter, for which the name Gelidibacter flavus sp. nov. is proposed. The type strain is Con4^T (=KEMB 41-198^T = JCM 31135^T).

Paenibacillus oryzisoli sp. nov., isolated from the rhizosphere of rice

A novel bacterium, strain 1ZS3-15^T, was isolated from rhizosphere of rice. Its taxonomic position was investigated using a polyphasic approach. The novel strain was observed to be Gram-stain positive, spore-forming, aerobic, motile and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 1ZS3-15^T was recovered within the genus Paenibacillus. It is closely related to Paenibacillus pectinilyticus KCTC 13222^T (97.9 % similarity), Paenibacillus frigoriresistens CCTCC AB 2011150^T (96.8 %), Paenibacillus alginolyticus JCM 9068^T (96.4 %) and Paenibacillus chondroitinus DSM 5051^T (95.5 %). The fatty acid profile of strain 1ZS3-15^T, which showed a predominance of anteiso-C_15:0 and iso-C_16:0, supported the allocation of the strain into the genus Paenibacillus. The predominant menaquinone was found to be MK-7. The polar lipids profile of strain 1ZS3-15^T was found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified lipid and two unidentified aminophospholipids. The cell wall peptidoglycan contains meso-diaminopimelic acid. Based on draft genome sequences, the DNA-DNA relatedness between strain 1ZS3-15^T and the closely related species P. pectinilyticus KCTC 13222^T are 24.2 ± 1.0 %, and the Average Nucleotide Identity values between the strains are 78.9 ± 0.1 %, which demonstrated that this isolate represents a new species in the genus Paenibacillus. The DNA G+C content was determined to be 45.3 mol%, which is within the range reported for Paenibacillus species. Characterisation by genotypic, chemotaxonomic and phenotypic analysis indicated that strain 1ZS3-15^T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus oryzisoli sp. nov. is proposed. The type strain is 1ZS3-15^T (= ACCC 19783^T = JCM 30487^T).