Immobilization of marine fungi on silica gel, silica xerogel and chitosan for biocatalytic reduction of ketones

Rocha, Lenilson C.; Souza, Adriano Lopes de; Rodrigues-Filho, Ubirajara P.; Filho, Sérgio Paulo Campana; Sette, Lara Durães; Porto, André Luiz Meleiro

doi:10.1016/j.molcatb.2012.05.025

Cited by 24 publications

(13 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The high chemoselectivity in the bioreduction of chalcones observed in the present study is probably not due to the lack of ADH activity in the yeast strains, rather to the steric hindrance given by the bulky phenyl substituents or to enzyme localization (not accessible to the substrates). Anyway, the bioreduction of C=O bond in ketones bearing bulky substituents was found in bacteria whole cells [43], as well as in other microorganism [44][45][46][47] such as algae, filamentous fungi, yeasts and in plant tissues [48].…”

Section: Resultsmentioning

confidence: 99%

Non-Conventional Yeasts as Sources of Ene-Reductases for the Bioreduction of Chalcones

et al. 2020

View full text Add to dashboard Cite

Thirteen Non-Conventional Yeasts (NCYs) have been investigated for their ability to reduce activated C=C bonds of chalcones to obtain the corresponding dihydrochalcones. A possible correlation between bioreducing capacity of the NCYs and the substrate structure was estimated. Generally, whole-cells of the NCYs were able to hydrogenate the C=C double bond occurring in (E)-1,3-diphenylprop-2-en-1-one, while worthy bioconversion yields were obtained when the substrate exhibited the presence of a deactivating electron-withdrawing Cl substituent on the B-ring. On the contrary, no conversion was generally found, with a few exceptions, in the presence of an activating electron-donating substituent OH. The bioreduction aptitude of the NCYs was apparently correlated to the logP value: Compounds characterized by a higher logP exhibited a superior aptitude to be reduced by the NCYs than compounds with a lower logP value.

show abstract

Section: Resultsmentioning

confidence: 99%

Non-Conventional Yeasts as Sources of Ene-Reductases for the Bioreduction of Chalcones

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The immobilization process may have brought about some changes in the physical properties, which favoured the action of ( R )-selective carbonyl reductases rather than ( S )-selective enzymes. Another possibility may be that the immobilization has activated another dehydrogenase which is different from the enzymes catalyzing the reduction in free cells [ 32 ]. However, a definite explanation about the inversion of configuration could still not be confirmed in the present study, and this issue is currently being investigated in our laboratory.…”

Section: Resultsmentioning

confidence: 99%

Immobilized and Free Cells of Geotrichum candidum for Asymmetric Reduction of Ketones: Stability and Recyclability

et al. 2018

View full text Add to dashboard Cite

Marine-derived fungus Geotrichum candidum AS 2.361 was previously reported by our group as an active strain for the enantioselective reduction of ketones. Although some other Geotrichum strains were also found from the terrestrial sources, information on their stability and reusability is scarce. Herein, the stabilities—in terms of pH tolerance, thermostability, and storage stability, and reusability—of G. candidum AS 2.361 were described for the asymmetric reduction of a series of aromatic ketones. Two differently immobilized cells (agar immobilization and calcium alginate immobilization) as well as free cells were prepared. For three substrates (1-(3-bromophenyl) ethan-1-one (1b), 1-(2-chlorophenyl) ethan-1-one (1d), and acetophenone (1g)) immobilized cells on agar showed a great improvement in the bioreduction activities compared to the free cells, increasing yields up to 97% with ee values of 99%. Cells immobilized on agar/calcium alginate could maintain more than 90% of the original activities within the assayed pH ranges of 3.5–11, while free cells were highly sensitive to alkaline and acidic conditions. Concerning thermostability, immobilized cells on agar kept 99% of their original activities after incubation at 60 °C for 1 h, while almost no activity was detected for the free cells under the same condition. Immobilized cells were stable at 4 °C for 80 days without any activity loss, while free cells started to decrease the activity after storage at 4 °C for six days. The immobilized cells retained almost 99% activity after four reuse cycles, while free cells lost almost all the activities at on the third cycle.

show abstract

“…Porto and his group [ 45 ] focused their research on the immobilization and evaluation of biocatalytic processes mediated by whole mycelia of the P. citrinum CBMAI 1186 and Aspergillus sclerotiorum CBMAI 849 strains using support matrices of silica gel, silica xerogel and chitosan. As mentioned above, the immobilization of the biocatalyst provides several benefits, such as the ability to recover the microorganisms, easy recovery of the product, etc.…”

Section: Bioreduction Of Prochiral Ketonesmentioning

confidence: 99%

Whole Cells as Biocatalysts in Organic Transformations

et al. 2018

View full text Add to dashboard Cite

Currently, the power and usefulness of biocatalysis in organic synthesis is undeniable, mainly due to the very high enantiomeric excess reached using enzymes, in an attempt to emulate natural processes. However, the use of isolated enzymes has some significant drawbacks, the most important of which is cost. The use of whole cells has emerged as a useful strategy with several advantages over isolated enzymes; for this reason, modern research in this field is increasing, and various reports have been published recently. This review surveys the most recent developments in the enantioselective reduction of carbon-carbon double bonds and prochiral ketones and the oxidation of prochiral sulfides using whole cells as biocatalytic systems.

show abstract

Immobilization of marine fungi on silica gel, silica xerogel and chitosan for biocatalytic reduction of ketones

Cited by 24 publications

References 23 publications

Non-Conventional Yeasts as Sources of Ene-Reductases for the Bioreduction of Chalcones

Non-Conventional Yeasts as Sources of Ene-Reductases for the Bioreduction of Chalcones

Immobilized and Free Cells of Geotrichum candidum for Asymmetric Reduction of Ketones: Stability and Recyclability

Whole Cells as Biocatalysts in Organic Transformations

Contact Info

Product

Resources

About