Ligno-Cellulose Degrading and Antimicrobial Activities of Selected Strains of Actinomycetes Isolated From Malaysian Rainforest Soils

Eighteen soil samples were collected from the tropical forest floor at Kuala Tahan National Park, Pahang. Soil Water content and soil pH were determined. Isolation of actinomycetes bacteria isolates was accomplished via multi-stage Dispersion and Differential Centrifugation (DDC) technique and total of 227 isolates were obtained and maintained on Starch-Casein Nitrate (SCN) medium. All soil samples gave high colony forming units (C.F.U.) counts when grown on medium of pH 7.0 (1.0-6.7 x 106) as compared to pH 5.0 (0.4-2.2 x 106). All isolates showed very diverse colony morphologies. Of 227 isolates, 24.67% (56/227) showed Xylanase activity, 28.63% (65/227) with Cellulase activity and 7.93% (18/227) for Galacto-mannanase. Antagonistic activities were also observed against plant pathogens of Xanthomonas campestris at 12.78% (29/227), Ralstonia solanacearum at 39.65% (90/227), Erwinia crysanthemi 0% (0/227) and Pantoea stewartii at 16.30% (37/227). Whereas in gram negative food pathogens of Salmonella typhimurium at 0.88% (2/227) and Vibrio parahaemolyticus at 6.61% (15/227). Antagonistic against gram positive food pathogens of Staphylococcus aureus was at 21.59% (49/227) and Listeria monocytogenes at 6.61% (15/227). Ten actinomycetes isolates (A3, C1, G2, G3, G4, G10, I15, L8, O15 and P5) were selected based on their bioactive compound profiles and subjected to microscopic studies, metabolic finger printing using BIOLOG system and partial 16S rDNA analysis. Significant and diverse differences between all 10 selected isolates were observed via BIOLOG carbon utilization profiling and cell morphology under light microscopy. Isolate G4 and O15 were identified as members of genus Kitasatospora while the other eight isolates belong to genus Streptomyces using 16S rDNA sequence analysis and light microscopy. The ability to produce extracellular enzymes and antagonism activity against plant pathogens indicated that the 10 selected isolates have potential to be consortia of microorganisms as inoculum in agrowaste composting such as oil palm’s empty fruit bunch. The inoculum not only increases the nutrient value in compost materials but also has advantage to control plant disease in soil ecosystem

{μ-6,6′-Dimeth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato}-μ-nitrato-dinitratoterbium(III)zinc(II)

In the title heteronuclear ZnII—TbIII complex (systematic name: {6,6′-dimeth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­id­yne)]diphenolato-1κ4 O 6,O 1,O 1′,O 6′}:2κ4 O 1,N,N′,O 1′-μ-nitrato-1:2κ2 O:O′-dinitrato-1κ4 O,O′-terbium(III)zinc(II)), [TbZn(C18H18N2O4)(NO3)3], with the hexa­dentate Schiff base compartmental ligand N,N′-bis­(3-methoxy­salicyl­idene)ethyl­enediamine (H2 L), the Tb and Zn atoms are triply bridged by two phenolate O atoms of the Schiff base ligand and one nitrate ion. The five-coordinate Zn atom is in a square-pyramidal geometry with the donor centers of two imine N atoms, two phenolate O atoms and one of the bridging nitrate O atoms. The TbIII center has a ninefold coordination environment of O atoms, involving the phenolate O atoms, two meth­oxy O atoms, two O atoms from two nitrate ions and one from the bridging nitrate ion. Weak inter­molecular C—H⋯O inter­actions generate a two-dimensional layer structure

Revocable, Interoperable and User-Centric (Active) Authentication Across Cyberspace

This work addresses fundamental and challenging user authentication and universal identity issues and solves the problems of system usability, authentication data security, user privacy, irrevocability, interoperability, cross-matching attacks, and post-login authentication breaches associated with existing authentication systems. It developed a solid user-centric biometrics based authentication model, called Bio-Capsule (BC), and implemented an (active) authentication system. BC is the template derived from the (secure) fusion of a user’s biometrics and that of a Reference Subject (RS). RS is simply a physical object such as a doll or an artificial one, such as an image. It is users’ BCs, rather than original biometric templates, that are utilized for user authentication and identification. The implemented (active) authentication system will facilitate and safely protect individuals’ diffused cyber activities, which is particularly important nowadays, when people are immersed in cyberspace. User authentication is the first guard of any trustworthy computing system. Along with people’s immersion in the penetrated cyber space integrated with information, networked systems, applications and mobility, universal identity security& management and active authentication become of paramount importance for cyber security and user privacy. Each of three typical existing authentication methods, what you KNOW (Password/PIN), HAVE (SmartCard), and ARE (Fingerprint/Face/Iris) and their combinations, suffer from their own inherent problems. For example, biometrics is becoming a promising authentication/identification method because it binds an individual with his identity, is resistant to losses, and does not need to memorize/carry. However, biometrics introduces its own challenges. One serious problem with biometrics is that biometric templates are hard to be replaced once compromised. In addition, biometrics may disclose user’s sensitive information (such as race, gender, even health condition), thus creating user privacy concerns. In the recent years, there has been intensive research addressing biometric template security and replaceability, such as cancelable biometrics and Biometric Cryptosystems. Unfortunately, these approaches do not fully exploit biometric advantages (e.g., requiring a PIN), reduce authentication accuracy, and/or suffer from possible attacks. The proposed approach is the first elegant solution to effectively address irreplaceability, privacy-preserving, and interoperability of both login and after-login authentication. Our methodology preserves biometrics’ robustness and accuracy, without sacrificing system acceptability for the same user, and distinguishability between different users. Biometric features cannot be recovered from the user’s Biometric Capsule or Reference Subject, even when both are stolen. The proposed model can be applied at the signal, feature, or template levels, and facilitates integration with new biometric identification methods to further enhance authentication performance. Moreover, the proposed active, non-intrusive authentication is not only scalable, but also particularly suitable to emerging portable, mobile computing devices. In summary, the proposed approach is (i) usercentric, i.e., highly user friendly without additional burden on users, (ii) provably secure and resistant to attacks including cross-matching attacks, (iii) identity-bearing and privacy-preserving, (iv) replaceable, once Biometric Capsule is compromised, (v) scalable and highly adaptable, (vi) interoperable and single signing on across systems, and (vii) cost-effective and easy to use