Removal of heavy oil from contaminated surfaces with a detergent formulation containing biosurfactants produced by Pseudomonas spp.

Industrial plants powered by heavy oil routinely experience problems with leaks in different parts of the system, such as during oil transport, the lubrication of equipment and mechanical failures. The surfactants, degreasing agents and solvents that make up detergents commonly used for cleaning grease-covered surfaces are synthetic, non-biodegradable and toxic, posing risks to the environment as well as the health of workers involved in the cleaning process. To address this problem, surfactant agents of a biodegradable nature and low toxicity, such as microbial surfactants, have been widely studied as an attractive, efficient solution to replace chemical surfactants in decontamination processes. In this work, the bacterial strains Pseudomonas cepacia CCT 6659, Pseudomonas aeruginosa UCP 0992, Pseudomonas aeruginosa ATCC 9027 and Pseudomonas aeruginosa ATCC 10145 were evaluated as biosurfactant producers in media containing different combinations and types of substrates and under different culture conditions. The biosurfactant produced by P. aeruginosa ATCC 10145 cultivated in a mineral medium composed of 5.0% glycerol and 2.0% glucose for 96 h was selected to formulate a biodetergent capable of removing heavy oil. The biosurfactant was able to reduce the surface tension of the medium to 26.40 mN/m, with a yield of approximately 12.00 g/L and a critical micelle concentration of 60.00 mg/L. The biosurfactant emulsified 97.40% and dispersed 98.00% of the motor oil. The detergent formulated with the biosurfactant also exhibited low toxicity in tests involving the microcrustacean Artemia salina and seeds of the vegetable Brassica oleracea. The detergent was compared to commercial formulations and removed 100% of the Special B1 Fuel Oil (OCB1) from different contaminated surfaces, demonstrating potential as a novel green remover with industrial applications.

تقييم فاعلية بعض المطهرات والمعقمات على البكتيريا الزائفة (Pseudomonas) المعزولة من وحدة العناية المركّزة للمواليد في مستشفى مصراتة المركزي - ليبيا

الملخص تهدف هذه الدراسة إلى تقييم مدى فاعلية وتأثير بعض المطهرات والمعقمات المستخدمة في المرافق الصحية، وخصوصًا في مستشفى مصراتة المركزي، بحسب التراكيز المعدّة لهذه المرافق، على مجموعة البكتيريا الزائفة (Pseudomonas) المعزولة من قسم الولادة ووحدة العناية المركّزة للأطفال حديثي الولادة بمستشفى مصراتة المركزي، في الفترة من 11 أكتوبر2017 إلى 8 مارس 2018، مع العامل الزمني لهذا التأثير، حيث كانت الأنواع المعزولة هي (Pseudomonas spp)، (Pseudomonas aeruginosa)، (pseudomallei Pseudomonas)، (Pseudomonas cepacia)، (Pseudomonas fluorescens)، (Pseudomonas luteola). وباستخدام أقراص ورق الترشيح المشبعة بالمعقم (Disk diffusion)، وكانت المعقمات والمطهرات، هي: (Ethanol)، (NaClO)، (Propanol AF)، (Desreson AF)، (Cidex)، (Decosept)، (Minuson AF)، (Dettol)، أظهرت النتائج تأخرًا في تأثير هذه المعقمات؛ إذ لم يظهر أي تأثير قبل 20 دقيقة من التعريض، وكان أكثرها فاعلية مطهر (Cidex) عند 20 دقيقة ضد الأنواع الثلاثة (P.cepacia) و(P. fluorescens) و(P.pseudomallei)، ثم بعد 24 ساعة لوحظت فاعلية جيدة على أغلب الأنواع للمعقمات (Decosept) و(NaClO) و(Dettol) و(Derseson)، ولكن ليس على كل الأنواع، مع فاعلية جيدة لمعقم (Propanol) على كل الأنواع، وتأثير خفيف لمطهر (Ethanol) ابتداء من الدقيقة 20، وانعدام أي تأثير لمعقم (Minuson) على هذه الأنواع، حيث تراوح حجم الهالة على هذه البكتيريا من 3 مليمترات إلى 2.5 سنتيمتر.

Characterisation of Some Selected Bacterial Isolates from Vegetable Oil Contaminated Soil

Microbial lipases occupy a place of prominence among biocatalysts and are often used for various biotechnological applications. Because of huge variation in applications, the availability of lipases with specific characteristics is still a limiting factor. There is therefore need for extensive characterisation of lipase for various applications. This work was carried out to characterise lipases from some selected bacterial isolates. Isolates identified as Bacillus subtilis, Bacillus licheniformis, Pseudomonas cepacia Pseudomonas fluorescens, Alcaligenes sp. and Flavobacterium sp. from a vegetable oil contaminated soil were characterized. Temperature, pH and ion concentration, (NaNO3 and MgSO4), incubation time, agitation speed, carbon sources and nitrogen sources were optimised for growth and lipase activity. Increase in microbial growth does not necessarily suggest increase in lipolytic activity as generally observed from this study. Temperature, pH, incubation time and agitation speed which had optimum enzyme activities for crude enzyme of Pseudomonas fluorescens (0.8 U/mL), were 27 oC, 7.0, 24 h, and 0 rpm respectively. Growth was not generally supported by AgN03 in all the organisms selected but supported by KNO3. However MgSO4 generally supported lipase production. Olive oil and peptone as sources of carbon and nitrogen respectively supported both growth and lipase production in the selected organisms. These bacterial isolates characterized had lipolytic activities, hence they have high potential for various biotechnological applications.

PDMAEMA/Polyester Miktopolymers: Synthesis via In-Out Approach, Physicochemical Characterization and Enzymatic Degradation

Synthesis, physicochemical characterization, and the enzymatic degradation of the amphiphilic miktoarm star-shaped polymers is reported herein. First, star-shaped macroinitiators, based on N,N′-dimethylaminoethyl methacrylate (DMAEMA) and glycerol dimethacrylate (GDMA) ((PDMAEMA)n-PGDMA), were synthesized. Due to the presence of hydroxyl groups in the macroinitiator core, polyesters such as poly(ɛ-caprolactone) (P(ɛ-CL)), polylactide (PLA) and poly(lactide-co-glycolide) (PLGA) were synthesized using ring opening polymerization (ROP). Comprehensive degradation studies on enzymatic degradation, using a lipase from Pseudomonas cepacia, were performed. Enzymatic degradation was monitored by weight measurements and nuclear magnetic resonance spectroscopy (1H NMR). The fastest degradation rate was observed for the polymer with the lowest molecular weight. Amphiphilic miktopolymers may find application as biomaterials for long- or mid-term period drug-delivery systems.

Lipase-Catalyzed Kinetic Resolution of Alcohols as Intermediates for the Synthesis of Heart Rate Reducing Agent Ivabradine

Ivabradine (Corlanor®), is a chiral benzocycloalkane currently employed and commercialized for the treatment of chronic stable angina pectoris and for the reduction in sinus tachycardia. The eutomer (S)-ivabradine is usually produced via chiral resolution of intermediates, by employing enantiopure auxiliary molecules or through preparative chiral HPLC separations. Recently, more sustainable biocatalytic approaches have been reported in literature for the preparation of the chiral amine precursor. In this work, we report on a novel biocatalyzed pathway, via a resolution study of a key alcohol intermediate used as a precursor of the chiral amine. After screening several enzymatic reaction conditions, employing different lipases and esterases both for the esterification and hydrolysis reactions, the best result was achieved with Pseudomonas cepacia Lipase and the final product was obtained in up to 96:4 enantiomeric ratio (e.r.) of an ivabradine alcohol precursor. This enantiomer was then efficiently converted into the desired amine in a facile three step synthetic sequence.

Amano Lipase PS from Burkholderia cepacia- Evaluation of the Effect of Substrates and Reaction Media on the Catalytic Activity

: Lipases in the native or immobilized form have commonly been used as catalysts in the chemical and pharmaceutical industry. One of the widely available enzyme catalysts on the market is lipase from Burkholderia cepacia (BCLs), previously called Pseudomonas cepacia (PCLs). This enzyme is applied, among others, in the stereoselective acylation of molecules to achieve chiral pure enantiomers of drugs or their building blocks. In this study, Amano lipase PS (APS-BCL), which is a commercial lipase from Burkholderia cepacia (BC) was tested. The lipolytic activity of APS-BCL by hydrolysis of vegetable oils and enantioselective activity of APS-BCL by the kinetic resolution of (R,S)-1-phenylethanol with using isopropenyl acetate as an acyl donor were evaluated. An effect of reaction media with different logP values (t-butyl methyl ether, dichloromethane, diisopropyl ether, toluene, cyclohexane, n-hexane, isooctane and n-heptane) on the enantioselective activity of lipase was also studied. The high value of the enantiomeric ratio (E =308.5) with the utilization of isopropenyl acetate was achieved. Whereas, the best reaction medium turned out to be diisopropyl ether, C =47.9%, eep =98%, ees =90%, after 24 h of incubation. Moreover, the influence of ω6/ω9 polyunsaturated fatty acids (PUFAs) ratio in commercial (peanut, camelina, rape, pumpkin seed, walnut, sesame, avocado, rice, corn, black cumin, hemp, safflower, grape seed) oils was investigated for the lipase activity. For the first time, the cut-off limit of ω6/ω9 ratio was proposed. The ratio equal to or higher than 2.3 allows achieving higher lipolytic activity.

Burkholderia cepacia Complex Bacteria: a Feared Contamination Risk in Water-Based Pharmaceutical Products

SUMMARY Burkholderia cepacia (formerly Pseudomonas cepacia) was once thought to be a single bacterial species but has expanded to the Burkholderia cepacia complex (Bcc), comprising 24 closely related opportunistic pathogenic species. These bacteria have a widespread environmental distribution, an extraordinary metabolic versatility, a complex genome with three chromosomes, and a high capacity for rapid mutation and adaptation. Additionally, they present an inherent resistance to antibiotics and antiseptics, as well as the abilities to survive under nutrient-limited conditions and to metabolize the organic matter present in oligotrophic aquatic environments, even using certain antimicrobials as carbon sources. These traits constitute the reason that Bcc bacteria are considered feared contaminants of aqueous pharmaceutical and personal care products and the frequent reason behind nonsterile product recalls. Contamination with Bcc has caused numerous nosocomial outbreaks in health care facilities, presenting a health threat, particularly for patients with cystic fibrosis and chronic granulomatous disease and for immunocompromised individuals. This review addresses the role of Bcc bacteria as a potential public health problem, the mechanisms behind their success as contaminants of pharmaceutical products, particularly in the presence of biocides, the difficulties encountered in their detection, and the preventive measures applied during manufacturing processes to control contamination with these objectionable microorganisms. A summary of Bcc-related outbreaks in different clinical settings, due to contamination of diverse types of pharmaceutical products, is provided.