The influence of detergent, the active component of detergent and sodiumtripolyphosphate on the biochemical process of some fungi.

Detergent "Merix" (Merima-Krusevac) and its components, sodiumtripolyphosphate and ethoxyled oleyl-cetyl alcohol in defined concentrations have influence on the enzymatic activity, bioproduction of amino acids and proteins and total biomass of species Aspergillus niger (A. niger) and Fusarium oxysporum (F. oxysporum). Detergent in concentration of 1% vol., in some cases, significantly stimulated production of the majority of amino acids. Detergent and its components (ethoxyled oleyl-cetyl alcohol and sodiumtripolyphosphate) in concentration of 1% vol. showed different influences on the production of proteins by the species of fungi A. niger and F. oxysporum. The enzymatic activity of fungi A. niger and F. oxysporum changed from total inhibition up to partial or total stimulation under influence of investigated pollutants. Detergent, sodiumtripolyphosphate and ethoxyled oleyl-cetyl alcohol, all in concentration of 1% vol. have reduced the production of the biomass of fungi A. niger and F. oxysporum. Investigated fungi have shown different response to the used pollutants.     

Metabolic activity of <Emphasis Type="Italic">Aspergillus niger</Emphasis> and <Emphasis Type="Italic">Fusarium lateritium</Emphasis> induced by ethoxylated oleyl cetyl alcohol and their bioremediation and biotechnological potential

The effect of ethoxylated oleyl cetyl alcohol (Henkel, Serbia) on the growth and metabolic activity of Aspergillus niger and Fusarium lateritium was in the focus of this paper. The fungi were isolated from wastewater of Lepenica River (Kragujevac, Serbia) at a place where municipal wastewater discharged into the river. The fungi were grown in Czapek-Dox liquid nutrient medium without and with addition of 0.5% pollutant. The physico-chemical and biochemical changes of pH, total biomass dry weight, quantity of free and total organic acids, proteolytic activity and quality of carbohydrates were evaluated from 4-th to 19-th day of fungal growth. The capacity of fungi to decrease concentration of pollutant in medium was determined by cobalt thiocyanate method. The pollutant caused an inhibitory effect on biomass dry weight of A. niger and F. lateritium for 8.50 and 30.61%, respectively. Among tested fungi, A. niger had the better biodegradation capacity (83%) than F. lateritium (65%). Alkaline protease activity of A. niger enhanced in the presence of pollutant for 7.6% whereas the enzyme of F. lateritium retained about 62.2% activity. Overall, the obtained results indicate the potential application of tested fungi in wastewater treatment, detergent industry and biotechnology.     

Potential of pure and mixed cultures of Cladosporium cladosporioides and Geotrichum candidum for application in bioremediation and detergent industry

The effect of ethoxylated oleyl–cetyl alcohol (Henkel, “Merima”, Serbia) on the growth and metabolic activity of Cladosporium cladosporioides, Geotrichum candidum and their mixed culture was in the focus of this paper. The cultures were grown in Czapek-Dox liquid nutrient medium with the addition of 0.5% pollutant and without it. The physico-chemical and biochemical changes of pH, the total biomass dry weight, the quantity of free and total organic acids, proteolytic activity and the quality of carbohydrates were evaluated from 4th to 19th day of fungal growth. The pollutant caused an inhibitory effect on biomass dry weight of C. cladosporioides and G. candidum for 10.36% and 4.65% respectively, and stimulatory effect on biomass of mixed culture for 3.80%. The pollutant had influence on the decrease in pH value of the media in the phase of culture growth, and pH changes were correlated with the amount of excreted total organic acids. The highest quantity of free and total organic acids was noted in media with pollutant of mixed culture and C. cladosporioides, respectively. The alkaline protease activities of C. cladosporioides, G. candidum and mixed culture were enhanced by addition of pollutant for 56.88%, 55.84% and 30.94% respectively. The obtained results indicate the potential of both pure and mixed cultures in mycoremediation environment contaminated by alcohol ethoxylated and detergent industry.     

Capacity of <Emphasis Type="Italic">Aspergillus niger</Emphasis> to Degrade Anionic Surfactants and Coproduce the Detergent Compatible Enzymes

The capacity of fungus Aspergillus niger to degrade anionic surfactants (AS) and coproduce the detergent compatible enzymes in a liquid Czapek-Dox medium supplemented with 0.3% powder detergent Merix (Henkel, Serbia) was examined in this study. The fungus was isolated from wastewater of Lepenica River (Kragujevac, Serbia), at a place where municipal wastewater discharged into the river. The concentration of AS in tested detergent and detergent-supplemented culture media was determined using a methylene blue active substances assay. The physico-chemical and biochemical changes of pH, redox potential, biomass dry weight, activities of alkaline protease and α-amylase were evaluated during fungal growth from 3-rd to 16- th day. The detergent caused an inhibitory effect on fungal growth and biomass dry weight (about 51.4%). Nevertheless, A. niger decomposed approximately 180.2 μg/mL or 30% of AS after 16 days. The results also showed that activities of alkaline protease and α-amylase were enhanced in presence of tested detergent for 372.0 and 12.7%, respectively. Overall, the obtained results indicate the potential application of fungus in wastewater treatment and detergent industry.     

Co-consumption of glucose and xylose for organic acid production by <Emphasis Type="Italic">Aspergillus carbonarius</Emphasis> cultivated in wheat straw hydrolysate

Aspergillus carbonarius exhibits excellent abilities to utilize a wide range of carbon sources and to produce various organic acids. In this study, wheat straw hydrolysate containing high concentrations of glucose and xylose was used for organic acid production by A. carbonarius. The results indicated that A. carbonarius efficiently co-consumed glucose and xylose and produced various types of organic acids in hydrolysate adjusted to pH 7. The inhibitor tolerance of A. carbonarius to the hydrolysate at different pH values was investigated and compared using spores and recycled mycelia. This comparison showed a slight difference in the inhibitor tolerance of the spores and the recycled mycelia based on their growth patterns. Moreover, the wild-type and a glucose oxidase deficient (Δgox) mutant were compared for their abilities to produce organic acids using the hydrolysate and a defined medium. The two strains showed a different pattern of organic acid production in the hydrolysate where the Δgox mutant produced more oxalic acid but less citric acid than the wild-type, which was different from the results obtained in the defined medium This study demonstrates the feasibility of using lignocellulosic biomass for the organic acid production by A. carbonarius.     

Efficient harvesting of <Emphasis Type="Italic">Synechocystis</Emphasis> sp. PCC 6803 with filamentous fungal pellets

Cyanobacteria play a major role as direct producers of biofuels, such as ethanol and butanol, with the aid of genetic engineering. However, development of a new harvesting-technology is essential to achieve economic viability of biofuel production from cyanobacteria. In this study, we demonstrated the feasibility of harvesting the unicellular cyanobacterium Synechocystis sp. PCC 6803 using pre-made filamentous fungal pellets and investigated key factors affecting efficiency of harvest, including fungal strain, pellet quantity (number of pellets), initial pH, and organic carbon source. Synechocystis sp. PCC 6803 cells attached to Aspergillus oryzae pellets, indicating that this fungal pellet had a desirable harvesting effect, while Rhizopus oryzae pellets had no effect on harvesting. Increasing pellet quantity and adding organic carbon sources, such as glucose and xylose, improved the harvesting efficiency of Aspergillus oryzae pellet; efficiency was not affected by the initial pH.     

The ectomycorrhizae of <Emphasis Type="Italic">Lactarius rimosellus</Emphasis> and <Emphasis Type="Italic">Lactarius acatlanensis</Emphasis> with the endangered <Emphasis Type="Italic">Fagus grandifolia</Emphasis> var. <Emphasis Type="Italic">mexicana</Emphasis>

Gut bacterium Pantoea sp. is one of the predominant bacterial species in the larval gut of the diamondback moth, Plutella xylostella. The phenotypic characters of Pantoea sp. were investigated with BIOLOG phenotype MicroArray (PM) in this study. Totally 950 different metabolic phenotypes were tested using the PM plates 1–10. Results exhibited that Pantoea sp. was able to metabolize 37.37 % of the tested carbon sources, 91.32 % of nitrogen sources, 100 % of sulfur sources, and 98.31 % of phosphorus sources. Most informative utilization patterns for carbon sources of Pantoea sp. were organic acids and carbohydrates, and for nitrogen were various amino acids. The bacterium had 94 different biosynthetic pathways. It had a wide range of adaptabilities, and could still metabolize in osmolytes with up to 9 % sodium chloride, 6 % potassium chloride, 5 % sodium sulfate, 20 % ethylene glycol, 4 % sodium formate, 4 % urea, 5 % sodium lactate, 200 mmol/L sodium phosphate (pH 7.0), 100 mmol/L ammonium sulfate (pH 8.0), 100 mmol/L sodium nitrate, and 100 mmol/L sodium nitrite, respectively. It also exhibited active metabolism under pH values between 4.5 and 10. Pantoea sp. showed active decarboxylase activities while poor deaminase activities in the presence of various amino acids. The phenotypic characterization of Pantoea sp. increased our knowledge of the bacterium, in particular its interactions with insect hosts and the adaptability in gut environments, and showed us some possible approaches to controlling diamondback moth through decreasing Pantoea sp. density.     

Bioconversion of Phenolic Monomers of Lignin and Lignin-Containing Substrates by the Basidiomycete <Emphasis Type="Italic">Lentinus tigrinus</Emphasis>

The bioconversion of phenolic monomers of lignin (veratrol, vanillin, and vanillyl alcohol), hydrolyzed lignin, and sodium lignosulfonate (a product of the chemical modification of native lignin) by the basidiomycete Lentinus tigrinus was studied. It was found that the growth of the fungi on lignin monomer compounds is suppressed. A noticeable growth of the fungal biomass was observed only on the technical substrate sodium lignosulfonate. A comprehensive physicochemical study of the products of microbial transformation of sodium lignosulfonate was performed. It was established that the main direction of lignin bioconversion is oxidative condensation to form humic substances. In this case, depolymerization of the phenolic skeleton of lignin to monomeric phenol derivatives did not occur. The aromatic carbon atoms of the phenolic skeleton, unlike the carbon atoms of polysaccharides, were not involved in the fungal biomass growth. The observed growth of the fungus on the technical substrate sodium lignosulfonate can be explained by the presence of admixtures of oligomeric polysaccharides hemicellulose and cellulose, which can be used by the fungus as a carbon source.     

Down-regulation of the caffeic acid <Emphasis Type="Italic">O</Emphasis>-methyltransferase gene in switchgrass reveals a novel monolignol analog

Background

Down-regulation of the caffeic acid 3-O-methyltransferase EC 2.1.1.68 (COMT) gene in the lignin biosynthetic pathway of switchgrass (Panicum virgatum) resulted in cell walls of transgenic plants releasing more constituent sugars after pretreatment by dilute acid and treatment with glycosyl hydrolases from an added enzyme preparation and from Clostridium thermocellum. Fermentation of both wild-type and transgenic switchgrass after milder hot water pretreatment with no water washing showed that only the transgenic switchgrass inhibited C. thermocellum. Gas chromatography–mass spectrometry (GCMS)-based metabolomics were undertaken on cell wall aqueous extracts to determine the nature of the microbial inhibitors.

Results

GCMS confirmed the increased concentration of a number of phenolic acids and aldehydes that are known inhibitors of microbial fermentation. Metabolomic analyses of the transgenic biomass additionally revealed the presence of a novel monolignol-like metabolite, identified as trans-3, 4-dimethoxy-5-hydroxycinnamyl alcohol (iso-sinapyl alcohol) in both non-pretreated, as well as hot water pretreated samples. iso-Sinapyl alcohol and its glucoside were subsequently generated by organic synthesis and the identity of natural and synthetic materials were confirmed by mass spectrometric and NMR analyses. The additional novel presence of iso-sinapic acid, iso-sinapyl aldehyde, and iso-syringin suggest the increased activity of a para-methyltransferase, concomitant with the reduced COMT activity, a strict meta-methyltransferase. Quantum chemical calculations were used to predict the most likely homodimeric lignans generated from dehydration reactions, but these products were not evident in plant samples.

Conclusions

Down-regulation of COMT activity in switchgrass resulted in the accumulation of previously undetected metabolites resembling sinapyl alcohol and its related metabolites, but that are derived from para-methylation of 5-hydroxyconiferyl alcohol, and related precursors and products; the accumulation of which suggests altered metabolism of 5-hydroxyconiferyl alcohol in switchgrass. Given that there was no indication that iso-sinapyl alcohol was integrated in cell walls, it is considered a monolignol analog. Diversion of substrates from sinapyl alcohol to free iso-sinapyl alcohol, its glucoside, and associated upstream lignin pathway changes, including increased phenolic aldehydes and acids, are together associated with more facile cell wall deconstruction, and to the observed inhibitory effect on microbial growth. However, iso-sinapyl alcohol and iso-sinapic acid, added separately to media, were not inhibitory to C. thermocellum cultures.

     

The influence of detergents and active components of detergent on bioproduction of organic matters and enzymatic activity of some species of fungi.

Detergent (Merix, "Merima " Krusevac) applied in concentration of 1% vol. showed specific influence on the bioproduction of some 15 different amino acids and on the enzyme activity of the species of fungi A. niger, A. alternata and T. roseum. Detergent has significantly stimulated the production of 15 analyzed amino acids of the fungi species A. niger. The same applied concentration of detergent has decreased or considerably decreased the production of some 14 of totally 15 analyzed amino acids of investigated fungi species A. alternata and T. roseum. The enzyme activity of the fungi A. niger was more intensive in relation to the species A. alternata and T. roseum during the experimental period or in some phases of the experimental period. The detergent component, ethoxyled oleyl-cetyl alcohol, in concentration of 0.01%, 0.1% and 1% showed an inhibitory effect, or significant inhibitory effect on the enzyme activity of the examined species of fungi (A. niger, A. alternata and T. roseum).     

Decreased mineral availability enhances rock phosphate solubilization efficiency in <Emphasis Type="Italic">Aspergillus niger</Emphasis>

Microbial solubilization of rock phosphate (RP) is mainly achieved by the production of organic acids and medium acidification through H⁺ release. During RP solubilization, mineral nutrient availability is likely to be critical for determining how much carbon is channeled either for metabolite synthesis or for microbial growth, influencing organic acid release by microorganisms. Thus, the objective of this work was to study the relationships between the concentration of mineral nutrients in the growth medium and the efficiency of RP solubilization by Aspergillus niger FS1. For this, the fungus was grown in Czapek medium containing 0, 1, 2, 10, 50, and 100 % of its original concentration of mineral nutrients. Decreasing mineral availability in the growth medium led to decreases in fungal biomass and solubilized P, and increases in titratable acidity and solubilization efficiency as expressed by mg solubilized P per g fungal biomass (Y_P/B), indicating a shift in fungal metabolism from biomass production to organic acid release. The transfer of pre-grown biomass to media with or without added minerals confirmed that lower mineral availability increases Y_P/B and led to the solubilization of 76 % of P present in Patos RP. These observations open new perspectives on improving RP solubilization systems by manipulating mineral nutrient availability in the medium, with consequent gains in cost reduction.     

Optimization of <Emphasis Type="Italic">Prochlorothrix hollandica</Emphasis> cyanobacteria culturing for obtaining myristoleic acid

Plankton filament cyanobacteria Prochlorothrix hollandica is characterized by a very high content of C₁₄ and C₁₆ fatty acids (FA) in the lipid membranes. Depending on culturing conditions of the cyanobacteria, total concentrations of myristic and myristoleic acids can reach 35% and those of palmitic and palmitoleic acids can reach 60% of all esterified FA cells. In P. hollandica, a variety of monounsaturated FA is represented by myristoleic and palmitic acids, and by hexadecenoic (C_16:1) acid with olefin bond of cis-configuration, located in the Δ4 position. The process of intensive culturing for P. hollandica cells to yield a maximal biomass in order to isolate the pure drug of myristoleic acid derivative has been optimized. The use of a threestage purification gives 30 mg of chromatographically pure myristoleic acid methyl ester from 17 g of P. hollandica raw biomass (dry mass is 3 g), which is 1% of dry cell mass.     

Low-cost cultivation of <Emphasis Type="Italic">Scenedesmus</Emphasis> sp. with filtered anaerobically digested piggery wastewater: biofuel production and pollutant remediation

A laboratory study was conducted on biomass and lipid production by Scenedesmus sp. and the removal of total nitrogen (TN) and total phosphorus (TP) from filtered anaerobically digested piggery wastewater. The dry weight (DW), lipid content and productivity, total nitrogen, and total phosphorus removal rate were assessed in five media: modified soil extract (MSE) medium, 5 % anaerobic digested wastewater (ADWW), 10 % ADWW, 15 % ADWW, and 5 % ADWW supplemented with NaNO₃. The highest biomass productivity appeared in the 15 % ADWW group, which was 20.4 % higher than MSE group. The highest lipid content was found in the 5 % ADWW group (31.60 %), while the highest lipid productivity was in the 10 % ADWW group (27.01 mg L^?1 day^?1). Compared with the 5 % ADWW group, the 5 % ADWW group supplemented with NaNO₃ had a similar biomass amount but lower lipid content and productivity. The fatty acids percentage of Scenedesmus sp. showed a slight difference in different media, but with the four dominant fatty acids (C16:0, C18:1, C18:2, C18:3) accounting for 87 % of the total fatty acids, suggests that Scenedesmus sp. in ADWW medium was no different than MSE in terms of lipid composition and content. TN removal rates were 82.85, 82.51, 85.85, 91.28, and 78.71 % in groups 1 to 5, and TP removal rates were 53.05, 88.53, 87.77, 88.72, and 80.64 %. Our experiment also shows the feasibility of using ADWW as a substitute of all the elements of MSE medium except for carbon, which would significantly reduce the costs of microalgal culture.     

A novel surfactant-, NaCl-, and protease-tolerant β-mannanase from <Emphasis Type="Italic">Bacillus</Emphasis> sp. HJ14

A glycoside hydrolase family 5 β-mannanase-encoding gene was cloned from Bacillus sp. HJ14 isolated from saline soil in Heijing town. Coding sequence of mature protein (without the predicted signal peptide from M1 to A30) was successfully expressed in Escherichia coli BL21 (DE3). Purified recombinant mannanase (rMan5HJ14) exhibited optimal activity at pH 6.5 and 65 °C. The enzyme showed good salt tolerance, retaining more than 56 % β-mannanase activity at 3.0–30.0 % (w/v) NaCl and more than 94 % of the initial activity after incubation with 3.0–30.0 % (w/v) NaCl at 37 °C for 60 min. Almost no mannanase activity was lost after incubation of rMan5HJ14 with trypsin, proteinase K, and Alcalase at 37 °C for 60 min. Surfactants and chelating agents, namely SDS, CTAB, Tween 80, Triton X-100, EDTA, and sodium tripolyphosphate, showed little or no effect (retaining >82.4 % activity) on enzymatic activity. Liquid detergents, namely Tupperware, Walch, Bluemoon, Tide, and OMO, also showed little or no effect (retaining >72.4 % activity) on enzymatic activity at 0.5–2.0 % (v/v). The enzyme further presents a high proportion (11.97 %) of acidic amino acid residues (D and E), which may affect the SDS and NaCl tolerance of the enzyme. Together, the mannanase may be an alternative for potential use in liquid detergent industry.     

Salt tolerance mechanisms in three Irano-Turanian Brassicaceae halophytes relatives of <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

Salt tolerance mechanisms were studied in three Irano-Turanian halophytic species from the Brassicaceae ??(Lepidium latifolium, L. perfoliatum and Schrenkiella parvula) and compared with the glycophyte Arabidopsis thaliana. According to seed germination under salt stress, L. perfoliatum was the most tolerant species, while L. latifolium and S. parvula were rather susceptible. Contrastingly, based on biomass production L. perfoliatum was more salt sensitive than the other two species. In S. parvula biomass was increased up to 2.8-fold by 100 mM NaCl; no significant growth reduction was observed even when exposed to 400 mM NaCl. Stable activities of antioxidative defense enzymes, nil or negligible accumulation of superoxide anion and hydrogen peroxide, as well as stable membrane integrity in the three halophytes revealed that no oxidative stress occurred in these tolerant species under salt stress. Proline levels increased in response to salt treatment. However, it contributed only by 0.3?2.0% to the total osmolyte concentration in the three halophytes (at 400 mM NaCl) and even less (0.04%) in the glycophyte, A. thaliana (at 100 mM NaCl). Soluble sugars in all three halophytes and free amino acids pool in S. parvula decreased under salt treatment in contrast to the glycophyte, A. thaliana. The contribution of organic osmolytes to the total osmolyte pool increased by salt treatment in the roots, while decreased in halophyte and glycophyte, A. thaliana leaves. Interestingly, this reduction was compensated by a higher relative contribution of K in the leaves of the halophytes, but of Na in A. thaliana. Taken together, biomass data and biochemical indicators show that S. parvula is more salt tolerant than the two Lepidium species. Our data indicate that L. latifolium, as a perennial halophyte with a large biomass, is highly suitable for both restoration of saline habitats and saline agriculture.     

Feasibility of 3D UV-C treatment to reduce fungal growth and mycotoxin loads on maize and wheat kernels

Fungal disease of grain crops is a concern for the agricultural industry, resulting in economic losses. Aside from severe yield losses, mycotoxigenic fungi such as Penicillium and Fusarium can produce harmful mycotoxins, including deoxynivalenol (DON), zearalenone (ZEN), and ochratoxin A (OTA). This proof-of-concept study explored the feasibility and effects of ultraviolet (UV) C light at 253.7 nm to reduce fungal and mycotoxin loads on model surfaces as well as on maize and wheat kernels using benchtop 2D and 3D illumination strategies. Reduction of Penicillium verrucosum (98.6%) and Fusarium graminearum (88.8%) on agar was achieved using a UV-C dose of 100 mJ cm^?2. Naturally occurring fungal growth resembling P. verrucosum on maize was reduced by 79% after exposure to 5000 mJ cm^?2. Similarly, fungal growth resembling F. graminearum on maize was reduced by 60% with 1000 mJ cm^?2. On wheat, significant reduction of fungal growth was not observed. Maximal reduction of DON (97.3%), ZEN (75.4%), and OTA (91.2%) on filter paper was obtained using 15,000 mJ cm^?2. The overall reduction of DON (30%; 14%), ZEN (52%; 42%), and OTA (17%; 6%) on maize and wheat, respectively, was lower than on filter paper. Moisture and crude protein content as well as percent germination of maize kernels were not affected by UV-C treatment up to 5000 mJ cm^?2. This study has shown that 3D UV-C treatment is a feasible option for reducing Fusarium and Penicillium growth on maize kernels and, at higher doses, decreasing ZEN by ~?50%.     

Performance of the biological aerated filter bioaugmented by a yeast <Emphasis Type="Italic">Magnusiomyces ingens</Emphasis> LH-F1 for treatment of Acid Red B and microbial community dynamics

Biological aerated filters (BAFs) were constructed and operated for assessing the effectiveness of bacterial community bioaugmented by a yeast Magnusiomyces ingens LH-F1 for treatment of azo dye Acid Red B (ARB). Dynamics of both bacterial and fungal communities were analyzed through MiSeq sequencing method. The results showed that the bioaugmented BAF displayed obviously better performance for decolorization, COD removal and detoxification of ARB wastewater than the other two which were inoculated with activated sludge (AS) and single M. ingens LH-F1, respectively. Moreover, the bioaugmented BAF also exhibited higher tolerance and stability to shock loading. MiSeq sequencing results demonstrated that both of bacterial and fungal communities remarkably shifted with operation conditions, and the increasing fungal diversity in the bioaugmented BAF was probably related to the relatively high biodegradation and detoxification efficiency. Furthermore, M. ingens LH-F1 survived in the bioaugmented BAF and became one of the dominant fungal species. Therefore, bioaugmentation with yeast M. ingens LH-F1 was successful for improving traditional biological processes aiming at treatment of azo compounds. This method was also potentially useful and meaningful for treating other recalcitrant organic pollutants in practical applications.     

<Emphasis Type="Italic">Haloquadratum walsbyi</Emphasis> Yields a Versatile,NAD<Superscript>+</Superscript>/NADP<Superscript>+</Superscript> Dual Affinity,Thermostable, Alcohol Dehydrogenase (<Emphasis Type="Italic">Hw</Emphasis>ADH)

This study presents the first example of an alcohol dehydrogenase (ADH) from the halophilic archaeum Haloquadratum walsbyi (HwADH). A hexahistidine-tagged recombinant HwADH was heterologously overexpressed in Haloferax volcanii. HwADH was purified in one step and was found to be thermophilic with optimal activity at 65 °C. HwADH was active in the presence of 10% (v/v) organic solvent. The enzyme displayed dual cofactor specificity and a broad substrate scope, and maximum activity was detected with benzyl alcohol and 2-phenyl-1-propanol. HwADH accepted aromatic ketones, acetophenone and phenylacetone as substrates. The enzyme also accepted cyclohexanol and aromatic secondary alcohols, 1-phenylethanol and 4-phenyl-2-butanol. H. walsbyi may offer an excellent alternative to other archaeal sources to expand the toolbox of halophilic biocatalysts.