Unprecedented Biodegradable Cellulose-Derived Polyesters with Pendant Citronellol Moieties: From Monomer Synthesis to Enzymatic Degradation

Levoglucosenone (LGO) is a cellulose-derived molecule that is present commercially on a multi-ton/year scale. Taking advantage of the α,β-conjugated ketone of LGO, a new citronellol-containing 5-membered lactone (HBO-citro) was synthesized through a one-pot two-step pathway involving oxa-Michael addition and Baeyer-Villiger oxidation. The solvent-free treatment of HBO-citro with NaBH4 at room temperature led to the full reduction of the lactone moiety which gave a novel fully renewable triol monomer having a citronellol side chain (Triol-citro). Noticeably, by simply changing the reducing agent, temperature and reaction duration, the partial reduction of HBO-citro can be achieved to yield a mixture of 5- and 6-membered Lactol-citro molecules. Triol-citro was chosen to prepare functional renewable polyesters having citronellol pendant chains via polycondensation reactions with diacyl chlorides having different chain lengths. Good thermal stability (Td5% up to 170 °C) and low glass transition temperatures (as low as −42 °C) were registered for the polyesters obtained. The polymers were then hydrolyzed using a commercial lipase from Thermomyces lanuginosus (Lipopan® 50 BG) to assess their biodegradability. A higher degradation profile was found for the polyesters prepared using co-monomers (acyl chlorides) having longer chain lengths. This is likely due to the decreased steric hindrance around the ester bonds which allowed enhanced accessibility of the enzyme.

Kinetic study of a commercial lipase for hydrolysis of semi-refined oil of anchovy (Engraulis ringens) [Estudio cinético de una lipasa comercial para la hidrólisis de aceite semirrefinado de anchoa (Engraulis ringens)]

Lipases due to their ecological nature and catalytic versatility, are ideal for their application in the fish oil hydrolysis industry due to their selective property, which allows the preservation of polyunsaturated fatty acids (PUFAs) in the lipid structure. The objective of this research was to determine the activity and kinetic parameters of a commercial AY AMANO "30SD" lipase, as well as the temperature and time values ​​to achieve an optimal degree of hydrolysis in semi-refined anchovy oil. The experiments were carried out in a jacketed minireactor with a working volume of 400 mL (oil-water-enzyme) with temperature control and pH 7.00, enzyme concentration 350 U/mL and stirring 160 rpm. A 3x3 factorial design and the response surface methodology were used. The results obtained from the study of the enzyme were: activity = 37 384.55 ± 395.07 U/g and kinetic parameters: Km = 7.98 g/L and Vmax. = 0.038887 g/Lxmin. Correspondingly, the following optimal parameters were obtained: Degree of hydrolysis 4.01%, temperature 46.86 °C and hydrolysis time 90 minutes, with a confidence level of 95% (p <0.05). Conclusions: The study allowed us to kinetically characterize the commercial lipase and determine the optimum degree of hydrolysis of the semi-refined anchovy oil.

Polymeric Nanoparticles Decorated with Monoclonal Antibodies: A New Immobilization Strategy for Increasing Lipase Activity

Recent advances in nanotechnology techniques enable the production of polymeric nanoparticles with specific morphologies and dimensions and, by tailoring their surfaces, one can manipulate their characteristics to suit specific applications. In this work we report an innovative approach for the immobilization of a commercial lipase from Candida rugosa (CRL) which employs nanostructured polymeric carriers conjugated with anti-lipase monoclonal antibodies (MoAbs). MoAbs were chemically conjugated on the surface of polymeric nanoparticles and used to selectively adsorb CRL molecules. Hydrolytic enzymatic assays evidenced that such immobilization technique afforded a significant enhancement of enzymatic activity in comparison to the free enzyme.

An Integrated Enzymatic Approach to Produce Pentyl Xylosides and Glucose/Xylose Laurate Esters From Wheat Bran

Alkyl glycosides and sugars esters are non-ionic surfactants of interest for various applications (cosmetics, food, detergency,…). In the present study, xylans and cellulose from wheat bran were enzymatically converted into pentyl xylosides and glucose and xylose laurate monoesters. Transglycosylation reaction catalyzed by the commercial enzymatic cocktail Cellic Ctec2 in the presence of pentanol led to the synthesis of pentyl β-D-xylosides from DP1 to 3 with an overall yield of 520 mg/g of xylans present in wheat bran. Enzymatic hydrolysis of wheat bran with Cellic Ctec2 and subsequent acylation of the recovered D-glucose and D-xylose catalyzed by the commercial lipase N435 in the presence of lauric acid or methyl laurate produced one D-glucose laurate monoester and one D-xylose laurate monoester. An integrated approach combining transglycosylation and (trans)esterification reactions was successfully developed to produce both pentyl xylosides and D-glucose and D-xylose laurate esters from the same batch of wheat bran.

Immobilization of Lipase CALB in Organically Modified Silica

In order to improve the activity of enzymes immobilized in silica, additives such as polyethylene glycol (PEG) can be introduced in the sol-gel process. This addition aims to protect the enzymes from denaturing effects by forming protection between the protein and the reaction medium. Thus, the aim of the work was to evaluate the effect of the use of the PEG additive in the process of immobilization of the commercial lipase of Candida antarctica B (CALB) in xerogel and aerogel obtained by the sol-gel technique. The mathematical model for the process was validated, and the optimum points determined were 0.09 g/ml of enzyme and 0.15 g/ml of polyethylene glycol additive for the xerogel and 0.12 g/ml of enzyme and 0.20 g/mL of polyethylene glycol additive for the aerogel. The maximum esterification activity and yield values were 544 U/g, 585%, and 266 U/g, 140% for xerogel and aerogel, respectively. Polyethylene glycol showed better performance in the esterification activity and stability as an additive when used in the xerogel, that is, when the process of obtaining the support uses the removal of the solvent only by evaporation. Regarding aerogel, a reduction in enzyme activity was observed, which may be due to the interaction of PEG with CO2 in the drying process.

Enrichment of Omega-3 from Anchovy (Stolephorus sp.) Fish Oil by Enzymatic Hydrolysis

Anchovy (Stolephorus sp.) is an economically important fish in Indonesia. Anchovy contains Omega-3 that important to maintain the health of the heart and brain. This study aimed to enrich the Omega 3 content of anchovy oil from the North Sea of West Java. The extraction of anchovy oil was carried out by the soxhlet method. Enrichment of omega 3 from anchovy fish oil is carried out by hydrolysis with a commercial lipase enzyme at concentration 500, 1000, 1500 and 2000 unit/600g fish oil, for 5, 10, 15 and 20 hour. Before hydrolysis, fish oil was added with solvent water, ethanol, toluene, and n-hexane. Omega 3 content of fish oil products were analyzed by using Gas Chromatography (GC) with FID detector with retention time 14.068 min and 15.506 min for α-Linolenat (ALA) and eicosapentaenoic (EPA), respectively. The results showed the highest omega 3 content (ALA 0.54% and EPA 1.103% ) was produced by addition n-hexane with a ratio 1:6 with the concentration of lipase was 1000 units for 20 hours.

Concentration of Lipase from Aspergillus oryzae Expressing Fusarium heterosporum by Nanofiltration to Enhance Transesterification

Nanofiltration membrane separation is an energy-saving technology that was used in this study to concentrate extracellular lipase and increase its total activity for biodiesel production. Lipase was produced by recombinant Aspergillus oryzae expressing Fusarium heterosporum lipase (FHL). A sulfonated polyethersulfone nanofiltration membrane, NTR-7410, with a molecular weight cut-off of 3 kDa was used for the separation, because recombinant lipase has a molecular weight of approximately 20 kDa, which differs from commercial lipase at around 30 kDa for CalleraTM Trans L (CalT). After concentration via nanofiltration, recombinant lipase achieved a 96.8% yield of fatty acid methyl ester (FAME) from unrefined palm oil, compared to 50.2% for CalT in 24 h. Meanwhile, the initial lipase activity (32.6 U/mL) of recombinant lipase was similar to that of CalT. The composition of FAME produced from recombinant concentrated lipase, i.e., C14:1, C16:0, C18:0, C18:1 cis, and C18:2 cis were 0.79%, 34.46%, 5.41%, 45.90%, and 12.46%, respectively, after transesterification. This FAME composition, even after being subjected to nanofiltration, was not significantly different from that produced from CalT. This study reveals the applicability of a simple and scalable nanofiltration membrane technology that can enhance enzymatic biodiesel production.