Isolasi Dan Karakterisasi Bakteri Penghasil Enzim Lipase Ekstraselulerdari Lumpur Aktif Instalasi Pengolahan Air Limbah Industri Tekstil

Lumpur aktif dari instalasi pengolahan air limbah industri tekstil mengandung berbagai jenis mikroorganisme antara lain mikroorganisme yang memiliki aktivitas lipase yang tinggi. Tujuan penelitian ini adalah mengisolasi dan mengkarakterisasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif instalasi pengolahan air limbah industri tekstil. Tahapan penelitian yang dilakukan meliputi isolasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif melalui skrining dengan media yang mengandung rodamin dan minyak zaitun, penentuan aktivitas enzim lipase dan karakterisasi lipase yang dihasilkan terhadap variasi temperatur, pH, dan pengaruh ion Ca2+. Hasil identifikasi secara mikrobiologi menunjukkan bahwa bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif adalah spesies Erwiniachrysantemi. Enzim lipase ekstraseluler tersebut memiliki aktivitas 4,75 U/mL dengan temperatur optimum 40oC dan pH optimum 9. Penambahan ion Ca2+ tidak memberikan pengaruh berarti terhadap aktivitas enzim lipase

ISOLASI DAN KARAKTERISASI BAKTERI PENGHASIL ENZIM LIPASE EKSTRASELULERDARI LUMPUR AKTIF INSTALASI PENGOLAHAN AIR LIMBAH INDUSTRI TEKSTIL

Lumpur aktif dari instalasi pengolahan air limbah industri tekstil mengandung berbagai jenis mikroorganisme antara lain mikroorganisme yang memiliki aktivitas lipase yang tinggi. Tujuan penelitian ini adalah mengisolasi dan mengkarakterisasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif instalasi pengolahan air limbah industri tekstil. Tahapan penelitian yang dilakukan meliputi isolasi bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif melalui skrining dengan media yang mengandung rodamin dan minyak zaitun, penentuan aktivitas enzim lipase dan karakterisasi lipase yang dihasilkan terhadap variasi temperatur, pH, dan pengaruh ion Ca2+. Hasil identifikasi secara mikrobiologi menunjukkan bahwa bakteri penghasil enzim lipase ekstraseluler dari lumpur aktif adalah spesies Erwiniachrysantemi. Enzim lipase ekstraseluler tersebut memiliki aktivitas 4,75 U/mL dengan temperatur optimum 40oC dan pH optimum 9. Penambahan ion Ca2+ tidak memberikan pengaruh berarti terhadap aktivitas enzim lipase

Isolation and Characterization of Organic-Solvent Stable Protease Isolated by Pseudomonas stutzeri BK AB-12

AbstractIn this study, proteases have been isolated from halophilic bacteria, Pseudomonas stutzeri BK AB-12. The bacteria produced proteases as exhibited by the appearance of clear zones resulted from casein hydrolysis. Based on the protease specific activity, 70−80% ammonium fraction exhibited the highest activity. Protease in this fraction has highest activity at pH 8.0 and 55°C and its activity of protease was enhanced by the addition of several metal ions. The addition of Fe3+ ion also resulted in a shifting of the optimum pH from 8 to 9 and the optimum temperature from 55 to 60°C. Protease of P. stutzeri BK AB-12 in the fraction of 70−80% is not likely metallo-, cysteine-, or serine-protease because it is not inhibited by EDTA, β-mercaptoethanol, and PMSF. Proteases of this fraction was sensitive to ionic strength, where the highest activity was observed at concentrations at NaCl concentrations of 2.5M. Beside influenced by the ionic strength, protease activity was also sensitive to solvent polarity. The protease wasstable in the presence of different organic solvents, which enables its potential use for the synthesis of peptides

A new group of glycoside hydrolase family 13 α-amylases with an aberrant catalytic triad

α-Amylases are glycoside hydrolase enzymes that act on the α(1→4) glycosidic linkages in glycogen, starch, and related α-glucans, and are ubiquitously present in Nature. Most α-amylases have been classified in glycoside hydrolase family 13 with a typical (β/α)8-barrel containing two aspartic acid and one glutamic acid residue that play an essential role in catalysis. An atypical α-amylase (BmaN1) with only two of the three invariant catalytic residues present was isolated from Bacillus megaterium strain NL3, a bacterial isolate from a sea anemone of Kakaban landlocked marine lake, Derawan Island, Indonesia. In BmaN1 the third residue, the aspartic acid that acts as the transition state stabilizer, was replaced by a histidine. Three-dimensional structure modeling of the BmaN1 amino acid sequence confirmed the aberrant catalytic triad. Glucose and maltose were found as products of the action of the novel α-amylase on soluble starch, demonstrating that it is active in spite of the peculiar catalytic triad. This novel BmaN1 α-amylase is part of a group of α-amylases that all have this atypical catalytic triad, consisting of aspartic acid, glutamic acid and histidine. Phylogenetic analysis showed that this group of α-amylases comprises a new subfamily of the glycoside hydrolase family 13

Structural basis for m7G-cap hypermethylation of small nuclear, small nucleolar and telomerase RNA by the dimethyltransferase TGS1

The 5′-cap of spliceosomal small nuclear RNAs, some small nucleolar RNAs and of telomerase RNA was found to be hypermethylated in vivo. The Trimethylguanosine Synthase 1 (TGS1) mediates this conversion of the 7-methylguanosine-cap to the 2,2,7-trimethylguanosine (m3G)-cap during maturation of the RNPs. For mammalian UsnRNAs the generated m2,2,7G-cap is one part of a bipartite import signal mediating the transport of the UsnRNP-core complex into the nucleus. In order to understand the structural organization of human TGS1 as well as substrate binding and recognition we solved the crystal structure of the active TGS1 methyltransferase domain containing both, the minimal substrate m7GTP and the reaction product S-adenosyl-l-homocysteine (AdoHcy). The methyltransferase of human TGS1 harbors the canonical class 1 methyltransferase fold as well as an unique N-terminal, α-helical domain of 40 amino acids, which is essential for m7G-cap binding and catalysis. The crystal structure of the substrate bound methyltransferase domain as well as mutagenesis studies provide insight into the catalytic mechanism of TGS1

Formation of m2G6 in Methanocaldococcus jannaschii tRNA catalyzed by the novel methyltransferase Trm14

The modified nucleosides N2-methylguanosine and N22-dimethylguanosine in transfer RNA occur at five positions in the D and anticodon arms, and at positions G6 and G7 in the acceptor stem. Trm1 and Trm11 enzymes are known to be responsible for several of the D/anticodon arm modifications, but methylases catalyzing post-transcriptional m2G synthesis in the acceptor stem are uncharacterized. Here, we report that the MJ0438 gene from Methanocaldococcus jannaschii encodes a novel S-adenosylmethionine-dependent methyltransferase, now identified as Trm14, which generates m2G at position 6 in tRNACys. The 381 amino acid Trm14 protein possesses a canonical RNA recognition THUMP domain at the amino terminus, followed by a γ-class Rossmann fold amino-methyltransferase catalytic domain featuring the signature NPPY active site motif. Trm14 is associated with cluster of orthologous groups (COG) 0116, and most closely resembles the m2G10 tRNA methylase Trm11. Phylogenetic analysis reveals a canonical archaeal/bacterial evolutionary separation with 20–30% sequence identities between the two branches, but it is likely that the detailed functions of COG 0116 enzymes differ between the archaeal and bacterial domains. In the archaeal branch, the protein is found exclusively in thermophiles. More distantly related Trm14 homologs were also identified in eukaryotes known to possess the m2G6 tRNA modification

The Critical Role of N- and C-Terminal Contact in Protein Stability and Folding of a Family 10 Xylanase under Extreme Conditions

Stabilization strategies adopted by proteins under extreme conditions are very complex and involve various kinds of interactions. Recent studies have shown that a large proportion of proteins have their N- and C-terminal elements in close contact and suggested they play a role in protein folding and stability. However, the biological significance of this contact remains elusive.In the present study, we investigate the role of N- and C-terminal residue interaction using a family 10 xylanase (BSX) with a TIM-barrel structure that shows stability under high temperature, alkali pH, and protease and SDS treatment. Based on crystal structure, an aromatic cluster was identified that involves Phe4, Trp6 and Tyr343 holding the N- and C-terminus together; this is a unique and important feature of this protein that might be crucial for folding and stability under poly-extreme conditions. folding and activity. Alanine substitution with Phe4, Trp6 and Tyr343 drastically decreased stability under all parameters studied. Importantly, substitution of Phe4 with Trp increased stability in SDS treatment. Mass spectrometry results of limited proteolysis further demonstrated that the Arg344 residue is highly susceptible to trypsin digestion in sensitive mutants such as ΔF4, W6A and Y343A, suggesting again that disruption of the Phe4-Trp6-Tyr343 (F-W-Y) cluster destabilizes the N- and C-terminal interaction. Our results underscore the importance of N- and C-terminal contact through aromatic interactions in protein folding and stability under extreme conditions, and these results may be useful to improve the stability of other proteins under suboptimal conditions

Antibacterial Activity of Endophytic Fungus Isolates of Mangrove Fruit (Sonneratia alba) Against Staphylococcus aureus and Esherichia coli

Endophytic fungi live and associate in plant tissues and have a mutualistic relationship. Endophytic fungi produce various compounds such as steroids, terpenoids, phenolics, alkaloids which are the same as secondary metabolites from their host plants. The objective of this study is to isolate and identify endophytic fungi from mangrove fruit (Sonneratia alba) and to determine the antibacterial activity of endophytic fungi isolates against the growth of Staphylococcus aureus and Escherichia coli. The type of research is pre-experimental design, one shoot case study. The methods used are isolation, identification and agar diffusion. The pieces of mangrove fruit were disinfected and then cultured on SDA media to grow endophytic fungi isolates. The isolates were cultured repeatedly until pure isolates were obtained. The test of isolate activity against antibacterial was determined by the agar diffusion method with the test material of 2 isolates of endophytic fungi on Nutrient Agar (NA) media. The results showed that the mangrove fruit (Sonneratia alba) produced two isolates of endophytic fungi that could inhibit the growth of Staphylococcus aureus and Escherichia coli. It was concluded that the mangrove fruit culture produced 2 isolates, which are isolate 1 Aspergillus niger and isolate 2 Aspergillus flavus. Isolate 1 and isolate 2 had the potential as antibacterial against the growth of Staphylococcus aureus and Escherichia coli. Isolate 2 was more effective than isolate 1 in inhibiting the growth of Staphylococcus aureus. It is recommended to test the pharmacological and microbiological activity of the findings of isolates 1 and 2 in vivo.Endophytic fungi live and associate in plant tissues and have a mutualistic relationship. Endophytic fungi produce various compounds such as steroids, terpenoids, phenolics, alkaloids which are the same as secondary metabolites from their host plants. The objective of this study is to isolate and identify endophytic fungi from mangrove fruit (Sonneratia alba) and to determine the antibacterial activity of endophytic fungi isolates against the growth of Staphylococcus aureus and Escherichia coli. The type of research is pre-experimental design, one shoot case study. The methods used are isolation, identification and agar diffusion. The pieces of mangrove fruit were disinfected and then cultured on SDA media to grow endophytic fungi isolates. The isolates were cultured repeatedly until pure isolates were obtained. The test of isolate activity against antibacterial was determined by the agar diffusion method with the test material of 2 isolates of endophytic fungi on Nutrient Agar (NA) media. The results showed that the mangrove fruit (Sonneratia alba) produced two isolates of endophytic fungi that could inhibit the growth of Staphylococcus aureus and Escherichia coli. It was concluded that the mangrove fruit culture produced 2 isolates, which are isolate 1 Aspergillus niger and isolate 2 Aspergillus flavus. Isolate 1 and isolate 2 had the potential as antibacterial against the growth of Staphylococcus aureus and Escherichia coli. Isolate 2 was more effective than isolate 1 in inhibiting the growth of Staphylococcus aureus. It is recommended to test the pharmacological and microbiological activity of the findings of isolates 1 and 2 in vivo