Production of poly-3-hydroxybutyrate (PHB) nanoparticles using grape residues as the sole carbon source.

The production of poly-3-hydroxybutyrate (PHB) on an industrial scale remains a major challenge due to its higher production cost compared to petroleum-based plastics. As a result, it is necessary to develop efficient fermentative processes using low-cost substrates and identify high-value-added applications where biodegradability and biocompatibility properties are of fundamental importance. In this study, grape residues, mainly grape skins, were used as the sole carbon source in Azotobacter vinelandii OP cultures for PHB production and subsequent nanoparticle synthesis based on the extracted polymer. The grape residue pretreatment showed a high rate of conversion into reducing sugars (fructose and glucose), achieving up to 43.3 % w w-1 without the use of acid or external heat. The cultures were grown in shake flasks, obtaining a biomass concentration of 2.9 g L-1 and a PHB accumulation of up to 37.7 % w w-1. PHB was characterized using techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The formation of emulsified PHB nanoparticles showed high stability, with a particle size between 210 and 240 nm and a zeta potential between -12 and - 15 mV over 72 h. Owing to these properties, the produced PHB nanoparticles hold significant potential for applications in drug delivery.

Assessing the Biodegradation of Vulcanised Rubber Particles by Fungi Using Genetic, Molecular and Surface Analysis.

Millions of tonnes of tyre waste are discarded annually and are considered one of the most difficult solid wastes to recycle. A sustainable alternative for the treatment of vulcanised rubber is the use of microorganisms that can biotransform polymers and aromatic compounds and then assimilate and mineralise some of the degradation products. However, vulcanised rubber materials present great resistance to biodegradation due to the presence of highly hydrophobic cross-linked structures that are provided by the additives they contain and the vulcanisation process itself. In this work, the biodegradation capabilities of 10 fungal strains cultivated in PDA and EM solid medium were studied over a period of 4 weeks. The growth of the strains, the mass loss of the vulcanised rubber particles and the surface structure were analysed after the incubation period. With the white rot fungi Trametes versicolor and Pleurotus ostreatus, biodegradation percentages of 7.5 and 6.1%, respectively, were achieved. The FTIR and SEM-EDS analyses confirmed a modification of the abundance of functional groups and elements arranged on the rubber surface, such as C, O, S, Si, and Zn, due to the biological treatment employed. The availability of genomic sequences of P. ostreatus and T. versicolor in public repositories allowed the analysis of the genetic content, genomic characteristics and specific components of both fungal species, determining some similarities between both species and their relationship with rubber biodegradation. Both fungi presented a higher number of sequences for laccases and manganese peroxidases, two extracellular enzymes responsible for many of the oxidative reactions reported in the literature. This was confirmed by measuring the laccase and peroxidase activity in cultures of T. versicolor and P. ostreatus with rubber particles, reaching between 2.8 and 3.3-times higher enzyme activity than in the absence of rubber. The integrative analysis of the results, supported by genetic and bioinformatics tools, allowed a deeper analysis of the biodegradation processes of vulcanised rubber. It is expected that this type of analysis can be used to find more efficient biotechnological solutions in the future.

[Dialogue between general practitioner and patient regarding tobacco and alcohol consumption, from the patient's standpoint]. / Dialogue entre médecin généraliste et patient : les consommations de tabac et d'alcool en question, du point de vue du patient.

BACKGROUND: General practitioners (GP) are key players in screening and counselling for smokers and alcohol drinkers exceeding French guidelines for low-risk consumption thresholds. Tackling the subject from the patients' perspective, the authors aim at estimating the proportion of the population having discussed their smoking and alcohol consumption with their GPs, and to pinpoint the factors associated with their having done so. METHODS: The data (n=6346) are derived from nationwide representative phone survey in mainland France conducted by the French public health monitoring center Baromètre de Santé publique France. RESULTS: Among the persons aged 18-75 having consulted a GP over the last 12 months (82.5%), 36.7% stated that smoking had been discussed in consultation while 16.8% had talked about alcohol use. For both substances, being a man, a smoker, an excessive alcohol user and having a chronic illness were not only independently associated with being questioned by one's doctor, but also with more frequent patient initiative. About 87% considered it normal to be asked by their GP about their alcohol intake, this proportion being higher among men and people with high incomes. CONCLUSION: Even though a large portion of the population would deem it normal to discuss smoking and alcohol intake in consultation with a GP, the subjects are rarely broached. Our results underline the need to bolster efforts at systematic screening for substance use by GPs.

Bacterial and enzymatic degradation of poly(cis-1,4-isoprene) rubber: Novel biotechnological applications.

Poly(cis-1,4-isoprene) rubber is a highly demanded elastomeric material mainly used for the manufacturing of tires. The end-cycle of rubber-made products is creating serious environmental concern and, therefore, different recycling processes have been proposed. However, the current physical-chemical processes include the use of hazardous chemical solvents, large amounts of energy, and possibly generations of unhealthy micro-plastics. Under this scenario, eco-friendly alternatives are needed and biotechnological rubber treatments are demonstrating huge potential. The cleavage mechanisms and the biochemical pathways for the uptake of poly(cis-1,4-isoprene) rubber have been extensively reported. Likewise, novel bacterial strains able to degrade the polymer have been studied and the involved structural and functional enzymes have been analyzed. Considering the fundamentals, biotechnological approaches have been proposed considering process optimization, cost-effective methods and larger-scale experiments in the search for practical and realistic applications. In this work, the latest research in the rubber biodegradation field is shown and discussed, aiming to analyze the combination of detoxification, devulcanization and polymer-cleavage mechanisms to achieve better degradation yields. The modified superficial structure of rubber materials after biological treatments might be an interesting way to reuse old rubber for re-vulcanization or to find new materials.

Enhancing the synthesis of latex clearing protein by different cultivation strategies.

In this study, we improved the synthesis of the latex clearing protein from Gordonia polyisoprenivorans VH2 (Lcp1VH2), a key enzyme for the initial cleavage of the rubber backbone. Cultivations using a recombinant strain of Escherichia coli were optimized to overcome poor solubility of Lcp1VH2 and improve the production yields. Different cultivation temperatures and agitation rates were evaluated in the process to demonstrate their impact on the solubility of Lcp1VH2. A specific maximum production rate of 28.3 mg Lcp1VH2 g-1 cell dry weight h-1 was obtained at 25 °C and at agitation rates between 200-300 rpm. The activity of Lcp1VH2 was strongly influenced by variations in the cultivation temperature with a specific maximum activity of 0.81 U mg-1 in cultures incubated at 30 °C. Besides cultivation-based optimization, also the strategy of fusion protein expression with NusA was successfully applied. The in vivo solubility of the Lcp1VH2 fusion protein was calculated to be 73.1%, which means an enhancement of 5.7-fold in comparison to the solubility of the native Lcp1VH2. The fusion protein of Lcp1VH2 and NusA still exhibited oxygenase activity with polyisoprene latex as a substrate. In fact, NusA-His-Lcp1VH2 reached a 4-fold higher volumetric activity in comparison to Lcp1VH2. Oligo(cis-1,4-isoprene) molecules were produced as degradation products due to the cleavage of the polymer backbone by NusA-His-Lcp1VH2. The formation of oligo-isoprenoid molecules with molecular weights between 236 and 984 Da were confirmed by electrospray ionization-mass spectrometry analysis.

[Smoking and vaping in France]. / Consommation de tabac et usage de cigarette électronique en France.

INTRODUCTION: The aim of the article is to present a summary of current knowledge on tobacco smoking in France available through representative population surveys. STATE OF ART: Smoking is very common in France as more than a quarter (28.7%) of 15-75years old individuals reported daily smoking in 2016. The rate is also high among 15-year-old (14.6%) and half of them (51.8%) have already smoked one cigarette. Since the 1970s, sex differences in smoking behaviour are narrowing. More recently, since 2000, smoking prevalence has tended to decrease among the most advantaged individuals but to increase among less advantaged ones. These social inequalities, which are becoming more and more pronounced, are being observed from smoking initiation, often before the age of 18. Daily users of E-cigarettes represent 2.5% of individuals from 15-75 years in France. They are also tobacco smokers (58.8%) or former smokers (41.2%). PERSPECTIVES: Taking social inequalities in health into consideration, notably regarding smoking initiation, is a key challenge in the fight against smoking. CONCLUSIONS: It is essential to strengthen efforts to decrease the rate of smoking in France. The 2017 Health Barometer and Escapad surveys will allow evaluation of the public policies implemented in 2016 and determine whether they have had an impact on the image of smoking and on smoking rates.

In vitro studies on the degradation of poly(cis-1,4-isoprene).

Cleavage of the backbone of poly(cis-1,4-isoprene) (IR) in solid rubber material was accomplished by the addition of partially purified latex clearing protein (Lcp1VH2 ) using a 200-mL enzyme reactor. Two strategies for the addition of Lcp1VH2 were studied revealing that the daily addition of 50 µg mL-1 of Lcp1VH2 for 5 days was clearly a more efficient regime in comparison to a one-time addition of 250 µg of Lcp1VH2 at the beginning. Soluble oligo(cis-1,4-isoprene) molecules occurred as degradation products and were identified by ESI-MS and GPC. Oxygenase activity of Lcp1VH2 with solid IR particles as substrate was shown for the first time by measuring the oxygen consumption in the reaction medium. A strong decrease of the dissolved oxygen concentration was detected at the end of the assay, which indicates an increase in the number of cleavage reactions. The oligo(cis-1,4-isoprene) molecules comprised 1 to 11 isoprene units and exhibited an average molecular weight (Mn ) of 885 g mol-1 . Isolation of the oligo(cis-1,4-isoprene) molecules was achieved by using silica gel column chromatography. The relative quantification of the isolated products was performed by HPLC-MS after derivatization with 2,4-dinitrophenilhydrazyne yielding a concentration of total degradation products of 1.62 g L-1 . Analysis of the polymer surface in samples incubated for 3 days with Lcp1VH2 via ATR-FTIR indicated the presence of carbonyl groups, which occurred upon the cleavage reaction. This study presents a cell-free bioprocess as an alternative rubber treatment that can be applied for the partial degradation of the polymer. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:890-899, 2018.

Cleavage of poly(cis-1,4-isoprene) rubber as solid substrate by cultures of Gordonia polyisoprenivorans.

Potential biotechnological recycling processes for rubber products include the bacterial degradation of poly(cis-1,4-isoprene) (IR) in order to achieve its total biodegradation or its biotransformation into useful products. The actinomycete Gordonia polyisoprenivorans strain VH2 catalyzes the degradation of IR and enables its use as a sole carbon source via ß-oxidation. The initial cleavage reaction is catalyzed by the extracellular latex clearing protein (Lcp). This dioxygenase is the key enzyme for the formation of oligo(cis-1,4-isoprene) molecules with different lengths, i.e., numbers of isoprene units. For the first time, IR was used as a solid substrate in 2-l fermenters. Two different particle size fractions (63-500 and 500-1000 µm) and three stirring rates (300, 400 and 500 rpm) were evaluated in the process. An increase of the cell concentration was achieved by using smaller particles and by using lower stirring rates, reaching a final biomass concentration of 0.52 g l-1 at 300 rpm after 12 days of cultivation. In order to enhance the formation of oligo(cis-1,4-isoprene) molecules, a transposon insertion mutant (TH5) of G. polyisoprenivorans strain VH2 that has lost the ability to transport the partial degradation products into the cells was used, thereby allowing the accumulation of the degradation products in the culture supernatants. Propionate, glucose and glycerol were evaluated as additional carbon sources besides IR, and the highest yields were observed on propionate. In 2-l bioreactors with pH control, different feeding regimes were performed during cultivation by the addition of propionate every 24 or 48 h for 16 days. After liquid-liquid extraction and a derivatization with Girard's T reagent, the oligo(cis-1,4-isoprene) molecules were detected by ESI-MS. The mass distribution of the degradation products was affected by the selection of the extraction solvent, but no influence of longer cultivation periods was detected.

A simple, rapid and cost-effective process for production of latex clearing protein to produce oligopolyisoprene molecules.

Aiming at finding feasible alternatives for rubber waste disposal, the partial enzymatic degradation of poly(cis-1,4-isoprene)-containing materials represents a potential solution. The use of rubber-degrading enzymes and the biotransformation of rubber into new materials is limited by the high costs associated with the production and purification of the enzyme and the complexity of the process. This study presents a simple and low-cost procedure to obtain purified latex clearing protein (Lcp), an enzyme capable of cleaving the double bonds of poly(cis-1,4-isoprene) in presence of oxygen to produce different size of oligomers with terminal aldehyde and ketone groups, respectively. The gene coding for Lcp1VH2 from Gordonia polyisoprenivorans strain VH2 was overexpressed in Escherichia coli C41 (DE3), and by using an auto-induction medium high protein yields were obtained. The cultivation process was described and compared with an IPTG-inducible medium previously used. Purification of the enzyme was performed using salting out precipitation with ammonium sulfate. Different salt concentrations and pH were tested in order to find the optimal for purification, obtaining a concentration of 60mg Lcp per l. The enzymatic activity of the purified enzyme was measured by an oxygen consumption assay in the presence of polyisoprene latex. Volumetric activities of 0.16Uml-1 were obtained at optimal conditions of temperature and pH. The results showed an active and partial purified fraction of Lcp1VH2, able to cleave the backbone of poly(cis-1,4-isoprene) and to produce degradation products that were identified with staining methodologies (Schiff reagent for aldehyde groups and 2,4-DNPH for carbonyl groups) and characterized using nuclear magnetic resonance (NMR). Thirteen different storage conditions were tested for the purified enzyme analyzing the enzymatic activity after 1 and 3 months. Lcp1VH2, as an ammonium sulfate precipitate, was stable, easy to handle and sufficiently active for further analysis. The described methodology offers the possibility to upscale the process and to produce large amounts of this protein.

Urodynamic findings in children with isolated epispadias.

PURPOSE: The exstrophy-epispadias complex represents a spectrum of anomalies with variable implications for upper and lower urinary tract function. Successful treatment of incontinence in this population is challenging and often elusive. To date few studies have focused on urodynamic findings specific to primary epispadias. MATERIALS AND METHODS: We retrospectively reviewed the records of patients presenting with primary epispadias in the absence of bladder exstrophy. We identified 18 boys and 12 girls, of whom 16 underwent formal urodynamic evaluation before (5), after (6) or before and after (5) surgical narrowing of the bladder neck. Bladder capacity was recorded as percent of expected capacity for age. Bladders were considered hypertonic when end filling pressure was greater than 20 cm. water. End filling pressure was defined as the pressure at which urinary leakage was noted or the patient had discomfort. Uninhibited contractions were considered significant when the amplitude was greater than 15 cm water. The ability of the detrusor to generate a voiding contraction at the end of the filling phase was also recorded. Urodynamic studies were performed with a balloon catheter occluding the incompetent bladder neck or with a standard urodynamic catheter after formal bladder neck repair. RESULTS: Before bladder neck repair average bladder capacity was 157 ml (range 55 to 450), corresponding to 52% (range 22 to 100) of expected capacity. Significant uninhibited contractions were noted in 2 patients. In 7 of the 9 evaluable patients (78%) a voiding contraction was generated. In children in whom urodynamic studies were done after surgery mean bladder capacity was 260 ml (range 77 to 660), corresponding to 76% (range 36 to 147) of expected capacity. Hypertonicity and hyperreflexia were noted in 3 and 2 patients, respectively. In 5 of the 11 cases (46%) a voiding bladder contraction was generated. Of the 5 patients who underwent urodynamic evaluation before and after bladder neck repair the percent increase in bladder capacity was significantly greater in the 2 boys (67 and 110%, respectively) than in the 3 girls (-20, 10 and 20, respectively). CONCLUSIONS: The most frequently noted urodynamic pattern before surgical correction of the bladder neck in patients with isolated epispadias is a low capacity, highly compliant bladder with minimal detrusor dysfunction. Postoperatively capacity increases, albeit to a greater extent in boys than in girls, and the incidence of detrusor dysfunction increases as well. In some patients classic bladder neck repair may result in detrimental bladder dynamics due to as yet poorly elucidated mechanisms.