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• Bioremediation failed to decontaminate a chronically oil-polluted soil. • Electrokinetic remediation (EKR) was combined with bioremediation. • Bioremediation was applied downstream of the EKR. • The sequential treatment exhibited high degradation performance. • The EKR induced a partial, albeit reversible, inhibition of the microbiota. This study focused on the remediation of a chronically diesel-polluted soil by combining an electrokinetic treatment with a variety of bioremediation approaches. Priority within the sequential treatment was given to electrokinetic remediation (EKR) since the application of natural attenuation (NA), biostimulation and site-specific bio-augmentation resulted in very low degradation performance for total petroleum hydrocarbons (TPH) and polycyclic hydrocarbons (PAH). The application of 20-day EKR (1.0 V cm−1 with polarity reversal) led to 47.2 % and 46.2 % removal of TPH and PAH, respectively, and exerted a negative impact on bacterial abundance, as determined indirectly by quantitative PCR of 16S rRNA genes and community function, as investigated by community-level physiological profiling. These adverse effects were transient and, after a 50-day NA treatment applied downstream from EKR, bacterial abundance was an order of magnitude higher than that found in the initial soil and TPH and PAH removals were significantly higher than those attained by EKR (64.1 % and 56.3 %, respectively). The combination of EKR with site-specific bioaugmentation led to the greatest TPH and PAH degradation (76.0 % and 78.6 %, respectively). The results indicate that bioremediation can be successfully applied downstream from EKR and that the adverse effects exerted by this physico-chemical approach on soil microbiota are reversible. [ABSTRACT FROM AUTHOR]

Microbial oils are regarded as a sustainable alternative to vegetable oils for biodiesel manufacturing. However, in order to develop a cost-effective process, high-lipid producer microorganisms should be combined with low-cost renewable growth substrates. For this reason, the objective of the present study was to assess comparatively the oil-producing performance of 9 oleaginous fungi belonging to the Aspergillus, Mucor, Mortierella and Cunninghamella genera on three relevant and widespread waste, such as glycerol, orange peel extract (OPE) and ricotta cheese whey (RCW). This screening was performed at the shaken flask level and, among the strains under study, Mortierella isabellina NRRL 1757 turned out to be the most efficient and versatile and its lipid profile was found to be highly compatible with biodiesel production. Process transfer of M. isabellina lipid production to the lab-scale Stirred Tank Reactor on all the three waste-based media, was shown to be feasible, achieving a lipid productivity of 0.46, 1.24 and 0.91 g/(L d) on glycerol, OPE and RCW, respectively. Noteworthy, the fatty acid analysis of the oils produced, confirmed their suitability for biodiesel manufacturing, exhibiting a high similarity to palm and Jatropha oils commonly used as feedstock for this production. [ABSTRACT FROM AUTHOR]

• Lipid production capacity of fungal strains compared on three waste-based media. • M. isabellina (Mi) was highly versatile in terms of growth and lipid production. • Mi lipid production was successfully transferred to lab-scale STR. • Mi lipid profiles resembled those of two commonly used oils (Jatropha and palm oil). Microbial oils are regarded as a sustainable alternative to vegetable oils for biodiesel manufacturing. However, in order to develop a cost-effective process, high-lipid producer microorganisms should be combined with low-cost renewable growth substrates. For this reason, the objective of the present study was to assess comparatively the oil-producing performance of 9 oleaginous fungi belonging to the Aspergillus , Mucor , Mortierella and Cunninghamella genera on three relevant and widespread waste, such as glycerol, orange peel extract (OPE) and ricotta cheese whey (RCW). This screening was performed at the shaken flask level and, among the strains under study, Mortierella isabellina NRRL 1757 turned out to be the most efficient and versatile and its lipid profile was found to be highly compatible with biodiesel production. Process transfer of M. isabellina lipid production to the lab-scale Stirred Tank Reactor on all the three waste-based media, was shown to be feasible, achieving a lipid productivity of 0.46, 1.24 and 0.91 g/(L d) on glycerol, OPE and RCW, respectively. Noteworthy, the fatty acid analysis of the oils produced, confirmed their suitability for biodiesel manufacturing, exhibiting a high similarity to palm and Jatropha oils commonly used as feedstock for this production. [ABSTRACT FROM AUTHOR]

The increasing demand of plant oils for biodiesel production has highlighted the need for alternative strategies based either on non-food crops or agro-industrial wastes that do not compete with food and feed production. In this context, the combined use of wastewater and oleaginous microorganisms could be a valuable production option. Ricotta cheese whey (RCW), one of the major byproducts of the dairy industry, is produced in very high and steadily increasing amounts and, due to its high organic load, its disposal is cost-prohibitive. In the present study, in order to assess the adequacy of RCW as a growth medium for lipid production, 18 strains of oleaginous yeasts were investigated in shaken flask for their growth and lipid-producing capabilities on this substrate. Among them, Cryptococcus curvatus NRRL Y-1511 and Cryptococcus laurentii UCD 68-201 adequately grew therein producing substantial amounts of lipids (6.8 and 5.1 g L − 1 , respectively). A high similarity between the percent fatty acid methyl esters (FAME) composition of lipids from the former and the latter strain was found with a predominance of oleic acid (52.8 vs. 48.7%) and of total saturated fatty acids (37.9 vs. 40.8%). The subsequent scale transfer of the C. laurentii UCD 68-201 lipid production process on RCW to a 3-L STR led to significantly improved biomass and total lipid productions (14.4 and 9.9 g L − 1 , respectively) with the biodiesel yield amounting to 32.6%. Although the C. laurentii FAME profile was modified upon process transfer, it resembled that of the Jatropha oil, a well established feedstock for biodiesel production. In conclusion, C. laurentii UCD 68-201, for which there is very limited amount of available information, turned out to be a very promising candidate for biodiesel production and wide margins of process improvement might be envisaged. [ABSTRACT FROM AUTHOR]

Abstract: An experimental biofuel wood chip storage site was studied, as a potential fungal “reservoir,” by means of quantitative and qualitative assessments of airborne fungal spores. Fungal load in the bio-aerosol, determined through active and passive methods, declined with the distance from wood piles. Occupational exposure was comparatively evaluated when two specific operational tasks, manual and mechanized handling, were performed. Under the conditions tested, the manual operators were more exposed to the airborne fungal spores (4864 ± 580 CFU m−3 air). The collected spores were identified as belonging to species of the genera Alternaria, Aspergillus, Penicillium, Fusarium, Cladosporium, Pleospora, Cochliobolus, Epicoccum, Absidia, and Trichoderma. Most prevalent were the genera Alternaria and Cladosporium, with the highest percentages of occurrence (30 and 12%, respectively). To the best of our knowledge, this is the first work reporting the identification through molecular methods of airborne fungi released during the handling of wood chip biofuel biomass. [Copyright &y& Elsevier]

Fungal strains naturally occurring on the wood and leaves of the salt-excreting desert tree Tamarix were isolated and characterized for their ability to produce cellulose- and starch-degrading enzymes. Of the 100 isolates, six fungal species were identified by ITS1 sequence analysis. No significant differences were observed among taxa isolated from wood samples of different Tamarix species, while highly salt-tolerant forms related to the genus Scopulariopsis (an anamorphic ascomycete) occurred only on the phylloplane of T. aphylla. All strains had cellulase and amylase activities, but the production of these enzymes was highest in strain D, a Schizophyllum-commune-related form. This strain, when grown on pretreated Tamarix biomass, produced an enzymatic complex containing levels of filter paperase (414 ± 16 IU/ml) that were higher than those of other S. commune strains. The enzyme complex was used to hydrolyze different lignocellulosic substrates, resulting in a saccha-rification rate of pretreated milk thistle (73.5 ± 1.2 %) that was only 10 % lower than that obtained with commercial cellulases. Our results support the use of Tamarix biomass as a useful source of cellulolytic and amylolytic fungi and as a good feedstock for the economical production of commercially relevant cellulases and amylases. [ABSTRACT FROM AUTHOR]

In this study a combination of both molecular and biochemical methods have been used to characterize the bacterial microbiota in water and sediment of a saline lake in Transylvania. The physicochemical characterization of the water samples from different lake depths indicated a stratification of the lake that affects the distribution of resident microorganisms, confirmed also by the significant differences in terms of functional diversity of the microbial communities in different water layers. The superficial bacterial community shows a good oxidative capability, degrading a wide range of organic substrates, yet the bottom layer community exhibits a major level of specialization. The membrane fatty acid analysis of the sediment bacterial community shows the prevalent presence of Gram negative bacteria, confirmed by the culturing techniques. Among the 24 collected isolates, 16S rRNA gene sequencing analysis permitted to identify 10 different species, belonging toBacillus,Halomonas,Idiomarina, Marinobacter, Pseudoalteromonas, Salinivibrio, Staphylococcusgenera and prevalently classified as halophiles. [ABSTRACT FROM PUBLISHER]

Abstract: The main aim of this study was to assess the ability of producing extracellular phenoloxidases (EPO) of fungi isolated from olive brine wastewater (OBW), the effluent from the debittering process of table olives. Five out of twenty isolates displayed EPO-producing ability as assessed by selective agar plate assays and were all halotolerant. Among them, Citeromyces matritensis (syn. Candida globosa) and Aspergillus fumigatus concomitantly produced laccase and Mn-peroxidase (MnP) activities. Candida boidinii and Candida bombi, instead, only produced laccase and Candida diddensiae only released MnP. Both C. matritensis and A. fumigatus, grown in shaken cultures on OBW, maintained their EPO-producing ability and removed phenols by 52.3 and 82.3%, respectively, after 10d incubation in the non-supplemented effluent. These results might suggest the possible use of these strains in the treatment of other saline phenol-rich effluents, such as pickling and tannery wastewater. [Copyright &y& Elsevier]

Abstract: Penicillium variabile P16 is characterized by the ability to release high levels of glucose oxidase when grown in glucose-rich media converting, at the same time, glucose into gluconic acid. This work reports on gluconic acid production by the above strain grown in bench-top reactor under different strategies, traditional batch and fed-batch processes; Na2CO3 was substituted for CaCO3 as the buffering agent in order to prevent calcium gluconate precipitation over the mycelium that would limit oxygen uptake and, as a consequence, glucose conversion. Best results were obtained with an improved fed-batch process which, in addition to glucose, was continuously fed with nitrogen and minerals at a flow rate of 0.02mlmin−1: yield and total productivity were 99.4% and 2.02gh−1, respectively, and remained constant till the end of the fermentation (240h). [Copyright &y& Elsevier]

Abstract: In this work the production of an extra-cellular β-glucan by Botryosphaeria rhodina DABAC P82, previously studied in a conventional bench-top stirred bioreactor, was enhanced by resorting to two different strategies consisting of dispersing different volumetric fractions of paraffin oil into the culture broth or replacing the six flat-blade Rushton turbines with 45° pitched four-blade open style (fan) turbines with different impeller-to-vessel diameter ratios (D/T). Use of fan turbines with D/T =0.54 at a tip impeller speed of 1.4ms−1 resulted in less viscous culture broths and most advantageous values of the β-glucan concentration (18.7±0.3kgm−3), and yield coefficients for β-glucan on mycelial biomass formed (5.1±0.8gg−1) and specific power consumed (23.3±0.4gW−1). [Copyright &y& Elsevier]

Abstract: Glucose oxidase (GOX) is a glycoprotein that finds wide application in food industry and clinical analysis. The gene encoding the GOX from Penicillium variabile P16 was expressed in Pichia pastoris X 33 using the methanol inducible AOX1 promoter. Among 11 transformants resistant toward high zeocin concentrations, six Mut+ strains were screened in shaken flasks and the strain X33 c9, producing 0.33Uml−1 of heterologous GOX after 11 days of fermentation, was selected. Recombinant GOX (ca. 50Uml−1) was produced in a 3-l fermenter under not optimized conditions, recovered and purified in order to characterize and to compare it with the native one. The GOX from P. pastoris had a molecular weight of 82kDa. Comparison of carbohydrate moieties showed a slight over-glycosylation of the GOX from Pichia over the native enzyme (17 and 14%, respectively). pH behavior of the recombinant enzyme, in terms of both activity and stability, was similar to that of the native one; on the other hand, a certain difference was observed in optimal temperature for activity and in thermal stability. P. pastoris appears to be a good expression system for GOX production. [Copyright &y& Elsevier]

Usage of ultrasonic field-based filters in retention of filamentous fungal cells was assessed using Rhizopus arrhizus NRRL 1526 as a model organism. Effects of operating conditions, such as power input, harvest pump flow rate, run time and stop time, on the system''s separation efficiency (SE) were evaluated by modulating the variables according to a Central Composite Design (CCD). The standard pump with which the ultrasonic filter was equipped was shown to be unsuitable and was, therefore, substituted for with a prime rate reverse pump that made possible separation and recycle of the mycelial biomass. The operating conditions were optimised (run time, 300 s; stop time, 3 s; power input, 6 W; harvest pump flow rate, 4 l per day) and a repeated batch process (three batches for a total of 192 h) was performed during which the SE was maintained always higher than 88%. [Copyright &y& Elsevier]

The production of seed oils from Cynara cardunculus generates huge amounts of lignocellulosic residues which can be exploited according to a cascade approach. In this paper, residual cardoon biomass (RCB) was tested as a growth substrate for the solid-state production of cellulolytic cocktails by species known to produce glucose-tolerant β-glucosidase isoenzymes. Best productions were obtained with 10- d -old Aspergillus tubingensis cultures on RCB supplemented with wheat bran (200 g kg−1) yielding β-glucosidase and endo-β-1,4-glucanase activities as high as (25 and 4) IU g−1, respectively, and 4 FPU g−1. The saccharification performance of the obtained cocktail tested on acid-catalysed steam-exploded RCB at low solid loading (25 g dm−3) was around 53% at 20 FPU g−1 cellulose. These performance were significantly enhanced by adding the xylanase-rich NS 22083 commercial formulation, reaching glucose yields higher than 80% after 72 h incubation. The use of the catalytic additive was optimized by a statistical approach, based on factorial analysis. A comparison of the performance of the A. tubingensis reinforced cocktail with the Cellic®CTec2 taken as benchmark formulation was done at the same enzyme load and performed at industrially relevant solid loadings, namely at (100 and 200) g dm−3. This comparison showed that Cellic®CTec2 led to only slightly higher glucose yields while an opposite outcome was observed for xylose yields, irrespective of the solid loading conditions. Thus, this study shows that an in-house enzyme production, based on the solid-state conversion of an industrial byproduct, able of yielding cellulolytic cocktails with substantial saccharification performance is feasible. • Residual cardoon biomass (RCB) from oil extraction needs to be exploited. • Significant levels of glycosyl hydrolases produced by A. tubingensis cultures on RCB. • Its cellulolytic cocktail leads to 53% saccharification at 20 FPU g−1 cellulose. • Saccharification performance of A. tubingensis cocktail (ATC) improved by xylanase. • ATC has similar performance on RCB compared to CTec2 commercial formulation. [ABSTRACT FROM AUTHOR]

Soil contamination constitutes a significant threat to the health of soil ecosystems in terms of complexity, toxicity, and recalcitrance. Among all contaminants, aliphatic petroleum hydrocarbons (APH) are of particular concern due to their abundance and persistence in the environment and the need of remediation technologies to ensure their removal in an environmentally, socially, and economically sustainable way. Soil remediation technologies presently available on the market to tackle soil contamination by petroleum hydrocarbons (PH) include landfilling, physical treatments (e.g., thermal desorption), chemical treatments (e.g., oxidation), and conventional bioremediation. The first two solutions are costly and energy-intensive approaches. Conversely, bioremediation of on-site excavated soil arranged in biopiles is a more sustainable procedure. Biopiles are engineered heaps able to stimulate microbial activity and enhance biodegradation, thus ensuring the removal of organic pollutants. This soil remediation technology is currently the most environmentally friendly solution available on the market, as it is less energy-intensive and has no detrimental impact on biological soil functions. However, its major limitation is its low removal efficiency, especially for long-chain hydrocarbons (LCH), compared to thermal desorption. Nevertheless, the use of fungi for remediation of environmental contaminants retains the benefits of bioremediation treatments, including low economic, social, and environmental costs, while attaining removal efficiencies similar to thermal desorption. Mycoremediation is a widely studied technology at lab scale, but there are few experiences at pilot scale. Several factors may reduce the overall efficiency of on-site mycoremediation biopiles (mycopiles), and the efficiency detected in the bench scale. These factors include the bioavailability of hydrocarbons, the selection of fungal species and bulking agents and their application rate, the interaction between the inoculated fungi and the indigenous microbiota, soil properties and nutrients, and other environmental factors (e.g., humidity, oxygen, and temperature). The identification of these factors at an early stage of biotreatability experiments would allow the application of this on-site technology to be refined and fine-tuned. This review brings together all mycoremediation work applied to aliphatic petroleum hydrocarbons (APH) and identifies the key factors in making mycoremediation effective. It also includes technological advances that reduce the effect of these factors, such as the structure of mycopiles, the application of surfactants, and the control of environmental factors. [ABSTRACT FROM AUTHOR]

Orange peel waste was converted into ethanol by consecutive acid-catalyzed steam-explosion (ACSE), enzymatic saccharification, and fermentation with Saccharomyces cerevisiae F15. With the aim of increasing the concentration of fermentable sugars in the hydrolysate and to fully recycle the spent acid liquor as the suspending medium for saccharification, the technical feasibility of increasing the solid loading in the ACSE step from 160 to 480 g L was assessed. At high solid loading in the ACSE pretreatment (HSLAP), the solubilization degrees of polysaccharides were lower while those of potential inhibitors (e.g., acetic and formic acids and phenols) were generally higher than those found at low solid loading (LSLAP). However, residual solids from both solid loadings showed similar susceptibility to enzymatic saccharification (ES) in a 7-L stirred-tank reactor (STR) (cellulase, 12 FPU g cellulose; pectinase, 25 IU g dry matter; 72 h incubation at 50 °C). Fermentation was performed in a 1-L STR along five repeated batches with the first one being used to enable yeast proliferation. By using the hydrolysates arising from the HSLAP-ES combination, it was possible to rely on a fermentation medium with a 2.5-fold higher concentration of simple sugars and to double the ethanol concentration in the final beer to be distilled of. However, the higher content of inhibitory compounds in hydrolysates from HSLAP-ES than in the LSLAP-ES ones led to a reduction in the ethanol yield per unit substrate consumed (0.49 vs. 0.41 g g, respectively) and overall productivity (3.4 vs. 2.7 g h, respectively). [ABSTRACT FROM AUTHOR]

Orange peel waste (OPW), the primary byproduct of the juice extraction process, is annually generated in massive amounts (21 Mton), and its aqueous extraction in biorefining operations yields a liquid fraction, referred to as orange peel extract (OPE). Although OPE contains significant amounts of easily assimilable carbohydrates, such as fructose, glucose, and sucrose, no investigations have been conducted yet to assess its possible use in biodiesel production by oleaginous yeasts. Consequently, the objective of the present study was to assess whether OPE might act as the basis of a liquid medium for microbial lipid production. A screening conducted with 18 strains of oleaginous yeasts in shaken flask on the OPE-based medium showed that Rhodosporidium toruloides NRRL 1091 and Cryptococcus laurentii UCD 68-201 gave the best results in terms of lipid production (5.8 and 4.5 g L−1, respectively) and accumulation (77 and 47% on a dry matter basis, respectively). The subsequent scale transfer of the process to a 3-L STR operated in batch mode halved the time required to reach the lipid peak with the ensuing increase in volumetric productivities in R. toruloides NRRL 1091 (3646 mg L−1 day−1) and C. laurentii UCD 68-201 (2970.7 mg L−1 day−1). The biodiesel yields from the lipids of the former and the latter strain were 36.9 and 31.9%, respectively. Based on multivariate analysis of fatty acid methyl ester compositions, the lipids from the former and the latter strain were highly resembling those of Jatropha and palm oils, two commonly used feedstocks for biodiesel manufacturing. [ABSTRACT FROM AUTHOR]

Fenton-like treatment (FLT) is an ISCO technique relying on the iron-induced H 2 O 2 activation in the presence of additives aimed at increasing the oxidant lifetime and maximizing iron solubility under natural soil pH conditions. The efficacy of FLT in the clean-up of hydrocarbon-contaminated soils is well established at the field-scale. However, a better assessment of the impact of the FLT on density, diversity and activity of the indigenous soil microbiota, might provide further insights into an optimal combination between FLT and in-situ bioremediation (ISB). The aim of this work was to assess the impacts of FLT on the microbial community of a diesel-contaminated soil collected nearby a gasoline station. Different FLT conditions were tested by varying either the H 2 O 2 concentrations (2 and 6%) or the oxidant application mode (single or double dosage). The impact of these treatments on the indigenous microbial community was assessed immediately after the Fenton-like treatment and after 30, 60 and 90 d and compared with enhanced natural attenuation (ENA). After FLT, a dramatic decrease in bacterial density, diversity and functionality was evident. Although in microcosms with double dosing at 2% H 2 O 2 a delayed recovery of the indigenous microbiota was observed as compared to those subjected to single oxidant dose, after 60 d incubation the respiration rate increased from 0.036 to 0.256 μg C CO 2 g −1 soil h −1 . Irrespective of the oxidant dose, best degradation results after 90 d incubation (around 80%) were observed with combined FLT, relying on double oxidant addition, and bioremediation. [ABSTRACT FROM AUTHOR]

Arundo donax L. has received much attention from researchers as biomass crop because of its vigorous growth, high productivity and low agronomic inputs requirements. Once harvested, the chopped biomass of A. donax L. may be stored for a variable period according to energy demand or logistic reasons. As consequence of storage, the chopped biomass may undergo processes of degradation that can compromise the energy yield of the product and the economic convenience of the cultivation. In the view of preserving the A. donax L. biomass for producing different kind of energy, such as bio-ethanol, biogas, and fuel for combustion, the aim of this study was to investigate, in small-scale, different storage systems assessing the dynamics of storage and their effects on energy losses and fuel quality. The work has included different studies, such as (i) the monitoring of heat development, moisture content and dry matter losses, (ii) the analysis of polymeric compounds and combustion performances. Results indicate that according to the storage method adopted, the conservation of the product can be significantly influenced, with clear impacts on its energy potential. Polymeric composition changed after storage according to the method used, while energetic characteristics were not remarkably affected. [ABSTRACT FROM AUTHOR]

The Bronze Age archaeological site of Shahr-i Sokhta (30° 39′ N; 61° 24’ E), located today in southeastern Iran, Sistan region, is a special archaeological deposit in which the exceptional preservation of human, plant and animal remains, due to the dry climate of the region, can provide detailed information on one of the first complex proto-urban societies. In recent years, there has been growing interest in changes in local climate and environment as major reasons why the settlement was abandoned about 4000 years ago. Food shortage has been regarded as a direct effect of these changes. No attention has been paid to the potential health hazards associated with ancient urban/domestic pollution, although large garbage deposits have been found in several parts of the site. During excavations in 2007, four soil samples were taken under aseptic conditions at a depth of 1.5–2 m in a stratified deposit sealed by the floor of a small house, dated to the second half of the third millennium BC. Microbiological, palynological, carpological and microanalytical studies were performed on the four soil samples. Site C was identified as the most affected by human activity. Failure of conventional methods of detecting culturable and unculturable microbes in site C indicated the need for specific culture conditions suggested by palynological observations. Since oat seed residues were identified among the archaeobotanical material, oat bran was used as carbon and energy source to make a new medium to revive microbes. Coarsely ground oat bran was sterilized twice and soaked with minimal medium as sole carbon source. About 50 mg of buried soil from site C was added to the medium in cell culture flasks with aerobic and anaerobic stoppers and incubated at 28–30 °C and at 4 °C. After incubation under aerobic and anaerobic conditions, five sporogenic microbes were identified by sequencing 16S rDNA and ITS rRNA regions: a sporogenic strain IRC3 identified as Bacillus sp. was the only isolate under anaerobic conditions, whereas under aerobic conditions four moulds were isolated: Aspergillus flavus IRC1, Penicillium crysogenum IRC2, Cladosporium sp. IRC4, and the psychrotroph Aspergillus restrictus IRC5. Bacillus sp., with 99.7% similarity to Bacillus subtilis , broke down oat bran, producing a gel, while Cladosporium sp., with 99.8% similarity to Cladosporium sphaerospermium, grew on oat bran by synthesizing intracellular lipids. All these microbes are known to spoil food and they are common where there is intense human activity. [ABSTRACT FROM AUTHOR]

Different applications of spent Agaricus bisporus substrate (SAS), a widespread agro-industrial waste, were investigated with respect to the remediation of a historically polluted soil with Polycyclic Aromatic Hydrocarbons (PAH). In one treatment, the waste was sterilized (SSAS) prior to its application in order to assess its ability to biostimulate, as an organic amendment, the resident soil microbiota and ensuing contaminant degradation. For the other treatments, two bioaugmentation approaches were investigated; the first involved the use of the waste itself and thus implied the application of A. bisporus and the inherent microbiota of the waste. In the second treatment, SAS was sterilized and inoculated again with the fungus to assess its ability to act as a fungal carrier. All these treatments were compared with natural attenuation in terms of their impact on soil heterotrophic and PAH-degrading bacteria, fungal growth, biodiversity of soil microbiota and ability to affect PAH bioavailability and ensuing degradation and detoxification. Results clearly showed that historically PAH contaminated soil was not amenable to natural attenuation. Conversely, the addition of sterilized spent A. bisporus substrate to the soil stimulated resident soil bacteria with ensuing high removals of 3-ring PAH. Both augmentation treatments were more effective in removing highly condensed PAH, some of which known to possess a significant carcinogenic activity. Regardless of the mode of application, the present results strongly support the adequacy of SAS for environmental remediation purposes and open the way to an attractive recycling option of this waste. [ABSTRACT FROM AUTHOR]

Highlights: [•] Antarctic fungus Lecanicillium muscarium chitinase production studied on shrimp and crab wastes. [•] The fungus produced quite high levels of enzymes on shrimp wastes. [•] Production of enzymes was optimized in bioreactor by RSM. [•] Optimized bioprocess in bioreactor yielded 137% more than that in shaken flasks. [•] Two cold-tolerant chitinolytic enzymes were purified and characterized. [ABSTRACT FROM AUTHOR]

Abstract: Nineteen bacterial isolates were grown in shaken cultures in media containing chitin as carbon source and different additional nitrogen sources such as yeast nitrogen base (YNB), yeast extract (YE), corn steep liquor (CSL) and ammonium sulfate. Strain BM17 showed the highest activity (200U/l) in medium containing Chitin (1%) and YNB (0.5%). Molecular analysis of the 16S rRNA gene showed that strain BM17 belongs to the species Paenibacillus pabuli (99.72% homology). The enzyme activity started after 12–24h; exponential enzyme production was recorded from the 24thh and lasted till the 96thh of incubation when activity peaked to decrease thereafter. Medium optimisation was carried out by Response Surface Methodology (RSM) considering the effects of chitin, corn steep liquor and yeast extract. BM17 chitinolytic activity was induced by chitin but the increase of its concentration did not have significant effects on the enzyme activity. By contrast, the nitrogen source, particularly YE, strongly affected the enzyme production. [Copyright &y& Elsevier]