Polyvinyl chloride (PVC) is a petroleum-based plastic used in various applications, polluting the environment because of its recalcitrance, large content of additives, and the presence of halogen. In our case study, a new, two-stage biodegradation technology that combined composting process used for PVC pretreatment with a subsequent PVC attack by newly-isolated fungal and bacterial strains under SSF conditions was used for biodegradation of commercial PVC films. The novelty consisted in a combined effect of the two biodegradation processes and the use for augmentation of microbial strains isolated from plastic-polluted environments. First, the ability of the newly-isolated strains to deteriorate PVC was tested in individual, liquid-medium- and SSF cultures. Higher mass-reductions of PVC films were obtained in the former cultures, probably due to a better mass transfer in liquid phase. Using the two-stage biodegradation technology the highest cumulative mass-reductions of 29.3 and 33.2% of PVC films were obtained after 110 days with Trichoderma hamatum and Bacillus amyloliquefaciens applied in the second stage in the SSF culture, respectively. However, FTIR analysis showed that the mass-reductions obtained represented removal of significant amounts of additives but the PVC polymer chain was not degraded.
- Klíčová slova
- Bacillus amyloliquefaciens, SSF culture, Trichoderma hamatum, biodeterioration, composting, polyvinyl chloride,
- Publikační typ
- časopisecké články MeSH
The removal efficiencies and the kinetics of disinfection byproducts (DBPs) were studied in six greenhouse laboratory-scale SSF CWs. Cattail (Typha latifolia) and its litter (collected from the aboveground samples of cattail in autumn) were used as a potential phytoremediation technology and as a primary substrate, respectively, for DBP removal. Results showed that most of the 11 DBPs (except chloroform and 1, 1-dichloropropanone) were efficiently removed (>90%) in six SSF CWs with hydraulic retention time of 5 d and there were no significant differences among the systems. Under the batch mode, the removal of DBPs in SSF CWs followed first-order kinetics with half-lives of 1.0-770.2 h. As a primary DBP in wastewater effluent, removal efficiencies for chloroform were higher in planted systems than in unplanted ones and plant uptake accounted for more than 23.8% of the removal. Plant litter greatly enhanced the removal of trihalomethanes (THMs) by supplying primary substrates and reducing conditions, and the formation of dichloromethane supported the anaerobic biodegradation of THMs via reductive dechlorination in SSF CWs. Trichloroacetonitrile was completely removed within 10 h in each system and hydrolysis was considered to be the dominant process as there was a rapid formation of the hydrolysis byproduct, trichloroacetamide.
- Klíčová slova
- Cattail litter, Disinfection byproducts, Subsurface-flow constructed wetlands (SSF CWs), Tertiary treatment, Typha latifolia,
- MeSH
- anaerobní bakterie metabolismus MeSH
- biodegradace MeSH
- chemické látky znečišťující vodu analýza metabolismus MeSH
- čištění vody metody MeSH
- dezinfekce metody MeSH
- kinetika MeSH
- mokřady * MeSH
- odpadní produkty analýza MeSH
- orobincovité MeSH
- podzemní voda chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chemické látky znečišťující vodu MeSH
- odpadní produkty MeSH
Sulfate is frequently found in the influent of subsurface-flow constructed wetlands (SSF CWs) used as tertiary treatments. To reveal the effects of plants and litters on sulfate removal, as well as the competition for organic carbon among microorganisms in SSF CWs, five laboratory-scale SSF CW microcosms were set up and were operated as a batch system with HRT 5 d. The results showed that the presence of Typha latifolia had little effect on sulfate removal in CWs, with or without additional carbon sources. Cattail litter addition greatly improved sulfate removal in SSF CWs. This improvement was linked to the continuous input of labile organic carbon, which lowers the redox level and supplies a habitat for sulfate reducing bacteria (SRB). The presence of SRB in cattail litter indicated the possibility of sulfate removal around the carbon supplier, but the quantity of microbes in cattail litter was much lower than that in gravel. Stoichiometry calculations showed that the contribution of SRB to COD removal (21-26%) was less than that of methane-producing bacteria (MPB) (47-61%) during the initial stage but dominated COD removal (42-65%) during the terminal stage. The contributions of aerobic bacteria (AB) and denitrification bacteria (DB) to COD removal were always lower than that of SRB. It was also observed that the variations in COD: S ratio had a great influence on the relative abundance of genes between SRB and MPB and both of them could be used as good predictors of carbon competition between SRB and MPB in CWs.
- Klíčová slova
- Carbon competition, Cattail litter, Subsurface flow constructed wetlands (SSF CWs), Sulfate, Sulfate reducing bacteria (SRB),
- MeSH
- Bacteria metabolismus MeSH
- biomasa MeSH
- chemické látky znečišťující vodu chemie metabolismus MeSH
- čištění vody metody MeSH
- mokřady * MeSH
- odpad tekutý - odstraňování * MeSH
- orobincovité fyziologie MeSH
- RNA ribozomální 16S MeSH
- sírany chemie metabolismus MeSH
- uhlík chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chemické látky znečišťující vodu MeSH
- RNA ribozomální 16S MeSH
- sírany MeSH
- uhlík MeSH
The effect of Typha latifolia and its litter on density and abundance of three denitrifying genes (nirS, nirK and nosZ) were investigated in six laboratory-scale SSF CW microcosms. Results showed that the copy numbers of nirS, nirK and nosZ in wetland microcosms were ranged between 10(8)-10(9), 10(6)-10(7) and 10(7)-10(8) copies g(-1), respectively. The presence of T. latifolia encouraged the growth of nirK containing bacteria. Addition of cattail litter could greatly stimulate the growth of bacteria containing nirS and nosZ gene. Path analysis illustrated that the presence of plants and litters had no significant direct impact on denitrifying genes, while it affected the denitrifying genes via alteration of dissolved oxygen and carbon sources.
- Klíčová slova
- Cattail litter, Denitrifying genes, Nitrate removal, Subsurface flow constructed wetlands (SSF CWs), Typha latifolia,
- MeSH
- Bacteria enzymologie genetika MeSH
- bakteriální geny * MeSH
- biologické modely MeSH
- biomasa * MeSH
- denitrifikace genetika MeSH
- mokřady * MeSH
- nitrátreduktasa genetika metabolismus MeSH
- RNA ribozomální 16S genetika MeSH
- rostliny mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- nitrátreduktasa MeSH
- RNA ribozomální 16S MeSH
This review provides current information on the production of ethanol from lignocellulosic biomass, with the main focus on relationships between process design and efficiency, expressed as ethanol concentration, yield and productivity. In spite of unquestionable advantages of lignocellulosic biomass as a feedstock for ethanol production (availability, price, non-competitiveness with food, waste material), many technological bottlenecks hinder its wide industrial application and competitiveness with 1st generation ethanol production. Among the main technological challenges are the recalcitrant structure of the material, and thus the need for extensive pretreatment (usually physico-chemical followed by enzymatic hydrolysis) to yield fermentable sugars, and a relatively low concentration of monosaccharides in the medium that hinder the achievement of ethanol concentrations comparable with those obtained using 1st generation feedstocks (e.g. corn or molasses). The presence of both pentose and hexose sugars in the fermentation broth, the price of cellulolytic enzymes, and the presence of toxic compounds that can inhibit cellulolytic enzymes and microbial producers of ethanol are major issues. In this review, different process configurations of the main technological steps (enzymatic hydrolysis, fermentation of hexose/and or pentose sugars) are discussed and their efficiencies are compared. The main features, benefits and drawbacks of simultaneous saccharification and fermentation (SSF), simultaneous saccharification and fermentation with delayed inoculation (dSSF), consolidated bioprocesses (CBP) combining production of cellulolytic enzymes, hydrolysis of biomass and fermentation into one step, together with an approach combining utilization of both pentose and hexose sugars are discussed and compared with separate hydrolysis and fermentation (SHF) processes. The impact of individual technological steps on final process efficiency is emphasized and the potential for use of immobilized biocatalysts is considered.
- Klíčová slova
- CBP, Enzymatic hydrolysis, Ethanol, Fermentation, Hexose, Immobilization, Lignocellulose, Pentose, Pretreatment, Process configuration, Productivity, SHF, SSF, Yield,
- MeSH
- biotechnologie metody MeSH
- ethanol metabolismus MeSH
- fermentace MeSH
- hydrolýza MeSH
- lignin metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- ethanol MeSH
- lignin MeSH
- lignocellulose MeSH Prohlížeč
OBJECTIVE: To compare the efficacy of two standard surgical procedures for post-hysterectomy vaginal vault prolapse in patients with levator ani avulsion. METHODS: This was a single-center, randomized interventional trial, of two standard surgical procedures for post-hysterectomy vaginal vault prolapse: Prolift Total vs unilateral vaginal sacrospinous colpopexy with native tissue vaginal repair (sacrospinous fixation, SSF), during the period from 2008 to 2011. Entry criteria included at least two-compartment prolapse, as well as complete unilateral or bilateral levator ani avulsion injury. The primary outcome was anatomical failure based on clinical and ultrasound assessment. Failure was defined clinically, according to the Pelvic Organ Prolapse Quantification system, as Ba, C or Bp at the hymen or below, and on translabial ultrasound as bladder descent to 10 mm or more below the lower margin of the symphysis pubis on maximum Valsalva maneuver. Secondary outcomes were evaluation of continence, sexual function and prolapse symptoms based on validated questionnaires. RESULTS: During the study period, 142 patients who were post-hysterectomy underwent surgery for prolapse in our unit; 72 of these were diagnosed with an avulsion injury and were offered participation in the study. Seventy patients were randomized into two groups: 36 in the Prolift group and 34 in the SSF group. On clinical examination at 1-year follow-up, we observed one (3%) case of anatomical failure in the Prolift group and 22 (65%) in the SSF group (P < 0.001). Using ultrasound criteria, there was one (2.8%) failure in the Prolift group compared with 21 (61.8%) in the SSF group (P < 0.001). The postoperative POPDI (Pelvic Organ Prolapse Distress Inventory) score for subjective outcome was 15.3 in the Prolift group vs 21.7 in the SSF group (P = 0.16). CONCLUSION: In patients with prolapse after hysterectomy and levator ani avulsion injury, SSF has a higher anatomical failure rate than does the Prolift Total procedure at 1-year follow-up.
- Klíčová slova
- 4D ultrasound, Prolift Total, SSF, levator avulsion, mesh, sacrospinous vaginal colpopexy, ultrasound assessment, vaginal prolapse surgery, vaginal sacrospinous fixation,
- MeSH
- bolest komplikace diagnostické zobrazování chirurgie MeSH
- chirurgické síťky * MeSH
- gynekologické chirurgické výkony metody MeSH
- hysterektomie vaginální škodlivé účinky MeSH
- koitus MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci anu komplikace diagnostické zobrazování chirurgie MeSH
- pánevní dno chirurgie MeSH
- pooperační komplikace diagnostické zobrazování chirurgie MeSH
- prolaps pánevních orgánů diagnostické zobrazování etiologie chirurgie MeSH
- průzkumy a dotazníky MeSH
- senioři MeSH
- stresová inkontinence moči etiologie MeSH
- ultrasonografie MeSH
- vagina diagnostické zobrazování patofyziologie chirurgie MeSH
- Valsalvův manévr MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
- srovnávací studie MeSH
It is not well understood how the ecological status and microbial community composition of spruce swamp forests (SSF) relate to those found in bogs and fens. To clarify this, we investigated biogeochemical parameters and microbial community composition in a bog, a fen and two SSF using high throughput barcoded sequencing of the small ribosomal subunit (SSU) variable region V4. The results demonstrated that the microbial community of SSF is positioned between those of bogs and fens, and this was confirmed by in silico predicted metabolic potentials. This corresponds well with the position of SSF on the trophic gradient and reflects distinct responses of microbial communities to environmental variables. Species richness and microbial diversity increased significantly from bog to fen, with SSF in between, reflecting the variation in pH, nutrient availability and peat decomposability. The archaeal community, dominated by hydrogenotrophic methanogens, was more similar in SSF and the bog compared with the fen. The composition of the bacterial community of SSF was intermediate between those of bog and fen. However, the production of CO2 (an indicator of peat decomposability) did not differ between SSF and bog, suggesting the limiting effect of low pH and poor litter quality on the functioning of the bacterial community in SSF. These results help to clarify the transitional position of SSF between bogs and fens and showed the strong effect of environmental conditions on microbial community composition and functioning.
- Klíčová slova
- Archaea, bacteria, bog, fen, microbial diversity, spruce swamp forest,
- MeSH
- Bacteria klasifikace genetika metabolismus MeSH
- biodiverzita MeSH
- Euryarchaeota klasifikace genetika metabolismus MeSH
- lesy * MeSH
- methan biosyntéza MeSH
- mikrobiální společenstva * MeSH
- mokřady * MeSH
- oxid uhličitý metabolismus MeSH
- počítačová simulace MeSH
- půda MeSH
- půdní mikrobiologie * MeSH
- smrk MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- methan MeSH
- oxid uhličitý MeSH
- půda MeSH
OBJECTIVE: The objective of the study was to compare recurrence and complication rates for sacrospinous fixation (SSF) and prolene mesh techniques for the primary treatment of posthysterectomy vaginal vault prolapse. STUDY DESIGN: Patients undergoing surgery for vault prolapse were included in a multicenter, randomized, controlled study comparing SSF or total mesh (Prolift; Gynecare/Ethicon, Somerville, NJ). The examination included pelvic organ prolapse quantification, urodynamics, ultrasound, and quality-of-life (QoL) questionnaires before and 3 and 12 months after surgery. RESULTS: Of 168 randomized patients, 83 underwent SSF and 85 mesh repair. Prolapse recurrence after 12 months occurred in 39.4% of the SSF group and in 16.9% of the mesh group (P = .003). The mesh exposure rate was 20.8%. No difference in QoL improvement as well as of de novo stress urinary incontinence and overactive bladder onset was found. CONCLUSION: Mesh exposure occurrence was balanced against a lower prolapse recurrence rate in the patients undergoing mesh surgery compared with those undergoing SSF.
- MeSH
- chirurgické síťky * MeSH
- hysterektomie škodlivé účinky MeSH
- kvalita života MeSH
- lidé středního věku MeSH
- lidé MeSH
- ligamenta chirurgie MeSH
- prolaps pánevních orgánů etiologie chirurgie MeSH
- průzkumy a dotazníky MeSH
- recidiva MeSH
- senioři MeSH
- stresová inkontinence moči chirurgie MeSH
- vagina chirurgie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
- srovnávací studie MeSH
Brewer's spent grain (BSG) is the main brewery industry by-product, with potential applications in the feed and food industries due to its carbohydrate composition. In addition, the lignocellulosic nature of BSG makes it an adequate substrate for carbohydrases production. In this work, solid-state fermentation (SSF) of BSG was performed with Aspergillus ibericus, a non-mycotoxin producer fungus with a high capacity to hydrolyze the lignocellulosic matrix of the agro-industrial by-products. SSF was performed at different scales to produce a crude extract rich in cellulase and xylanase. The potential of the crude extract was tested in two different applications: -(1) - the enzymatic hydrolysis of the fermented BSG and (2) - as a supplement in aquafeeds. SSF of BSG increased the protein content from 25% to 29% (w/w), while the fiber content was reduced to 43%, and cellulose and hemicellulose contents were markedly reduced to around 15%. The scale-up of SSF from 10 g of dry BSG in flasks to 50 g or 400 g in tray-type bioreactors increased 55% and 25% production of cellulase and xylanase, up to 323 and 1073 U g-1 BSG, respectively. The optimum temperature and pH of maximal activities were found to be 55°C and pH 4.4 for xylanase and 50°C and pH 3.9 for cellulase, cellulase being more thermostable than xylanase when exposed at temperatures from 45°C to 60°C. A Box-Behnken factorial design was applied to optimize the hydrolysis of the fermented BSG by crude extract. The crude extract load was a significant factor in sugars release, highlighting the role of hydrolytic enzymes, while the load of fermented BSG, and addition of a commercial β-glucosidase were responsible for the highest phenolic compounds and antioxidant activity release. The lyophilized crude extract (12,400 and 1050 U g-1 lyophilized extract of xylanase and cellulase, respectively) was also tested as an enzyme supplement in aquafeed for European seabass (Dicentrarchus labrax) juveniles. The dietary supplementation with the crude extract significantly improved feed and protein utilization. The processing of BSG using biological treatments, such as SSF with A. ibericus, led to the production of a nutritionally enriched BSG and a crude extract with highly efficient carbohydrases capable of hydrolyzing lignocellulosic substrates, such as BSG, and with the potential to be used as feed enzymes with remarkable results in improving feed utilization of an important aquaculture fish species.
- Klíčová slova
- aquaculture, brewer’s spent grain, carbohydrases, enzymatic hydrolysis, solid-state fermentation,
- Publikační typ
- časopisecké články MeSH
The solid-state fluorescence (SSF) of eight DPA-DPS-EWG derivatives (DPA = diphenylamino, DPS = 2,5-diphenyl-stilbene building block, EWG = electron withdrawing group) was studied. Varying the strength of the EWG enabled the tuning of the LUMO energy within a range broader than 1 eV, while the simultaneous changes of HOMO energy were less than 0.1 eV, according to cyclic voltammetry. The fluorescence maxima in dichloromethane laid between 483 and 752 nm and exhibited monoexponential decay and a photoluminescence quantum yield (PLQY) always higher than 35%. Six derivatives with a SSF PLQY higher than 10% in polycrystalline powder form continuously covered the range from 475 to 733 nm. Three components of SSF multiexponential decay, obtained by time-resolved fluorescence spectroscopy, were ascribed to exciton migration to nonfluorescent traps, and monomer-like and aggregate fluorescence. The character of the emitting aggregates was evaluated by quantum chemical modelling based on time-dependent density functional theory computations, carried out on the dimer arrangements obtained by X-ray diffractometry of the single crystals.
- Publikační typ
- časopisecké články MeSH
