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Order Cirlivirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
To achieve high-level expression of the PCV2 Cap in methylotrophic yeast Pichia pastoris, the wild-type Cap gene was codon-optimized, and the intracellular soluble opti-Cap reached high 174 μg/mL without concentration in a shake flask, whereas the wt-Cap could not be detectable (Tu et al. 2013). However, the putative VLP-or-not status of the efficiently produced Cap was not addressed. Xiao et al. (2018) used yeast Hansenula polymorpha to express an NLS-deleted capsid protein ΔCat of PCV2b based on the capsid protein of the PCV2b strain Y-7 isolated in China. The purified ΔCat self-assembled into the VLPs with similar morphology of the VLPs formed by the Cat and induced high levels of specific antibodies in mice (Xiao et al. 2018). At last, the efficient production of the PCV2 VLPs was demonstrated in a nonconventional yeast Kluyveromyces marxianus (Duan et al. 2019). After codon optimization, the synthesized PCV2 Cap assembled spontaneously into VLPs and reached ~1.91 g/L of PCV2 VLP antigen in a 5-L bioreactor after high cell density fermentation for 72 h. That yield greatly exceeded to the earlier reported production by baculovirus-insect cells, E. coli and P. pastoris. By the means of two-step chromatography, 652.8 mg of PCV2 VLP antigen was obtained from 1 L of the recombinant K. marxianus cell culture. The PCV2 VLPs induced high levels of anti-PCV2 IgG antibody in mice and decreased the virus titers in both livers and spleens of the challenged mice (Duan et al. 2019).
Biotransformation of Sesquiterpenoids, Ionones, Damascones, Adamantanes, and Aromatic Compounds by Green Algae, Fungi, and Mammals
Published in K. Hüsnü Can Başer, Gerhard Buchbauer, Handbook of Essential Oils, 2020
Yoshinori Asakawa, Yoshiaki Noma
El Sayed et al. (2002) reported microbial and chemical transformation of (S)-(+)-curcuphenol (282 g) and curcudiol (282n), isolated from the marine sponges Didiscus axiata. Incubation of compound 282 g with Kluyveromyces marxianus var. lactis resulted in the isolation of six metabolites (3–8, 282h–282j). The same substrate was incubated with Aspergillus alliaceus to give the metabolites (282p, 282q, 282 s) (Figure 23.87).
Candida
Published in Dongyou Liu, Laboratory Models for Foodborne Infections, 2017
María Jesús Andrade, Mar Rodríguez, Alicia Rodríguez, Juan José Córdoba
Since the Candida genus is integrated by asexual yeast species, several other genera have Candida anamorphs. Thus, some Candida anamorphs are frequently found in some food such as Debaryomyces hansenii (anamorph C. famata) or Kluyveromyces marxianus (anamorph C. kefyr). It should be noted that both species are used as commercial starter cultures and are included in the QPS (Qualified Presumption of Safety) list developed by the European Food Safety Authority (EFSA).23C. kefyr appears to be an emerging pathogen.3 Nevertheless, until now, there are no safety concerns about the use of K. marxianus because of the history of its apparent safe use and the rarity of its infections in human beings.24C. famata, found in food products such as cheese and meat products,12,18,25 has been associated with occasional infections.3,8,9,23–25
Cancer Chemopreventive, Antiproliferative, and Superoxide Anion Scavenging Properties of Kluyveromyces marxianus and Saccharomyces cerevisiae var. boulardii Cell Wall Components
Published in Nutrition and Cancer, 2018
Olivier Fortin, Blanca Aguilar-Uscanga, Khanh Dang Vu, Stephane Salmieri, Monique Lacroix
Kluyveromyces marxianus ATCC 10022 and Saccharomyces cerevisiae var. boulardii ATCC MYA-796 were purchased from American type culture collection (ATCC) (Manassas, VA, USA). The yeast strains were stored at −80°C in sterile yeast peptone dextrose (YPD) (10 M dextrose, 5 M yeast extract, 3 M bacterial peptone, 0.8 M MgSO4, 1 M KH2PO4) containing 10% (w/v) sterile glycerol. One milliliter of culture cells in cryovial (108 cells/ml) from each strain were thawed and inoculated in a 125 ml Erlenmeyer containing 25 ml of YPD medium then incubated for 18 h at 30°C at 200 rpm (Forma Scientific, Orbital shaker, Model; EQ-069, USA). A quantity of 2.5 ml of the resulting cell suspension was inoculated in a 250 Erlenmeyer containing a final volume of 50 ml of YPD medium for 24 h at 30°C under agitation. Finally, 12.5 ml of this second cell suspension was inoculated in a 1l Erlenmeyer containing a final volume of 250 ml of YPD medium for 24 h at 30°C under agitation. At the end of second and third growth, 1 ml of fermented broth was serially diluted in sterile peptone water and plated on YPD agar in order to confirm lack of contamination in cell suspension. To obtain sufficient cell wall extract, this procedure was repeated in triplicate (n = 3) for each strain.
Bacterial-fungal metabolic interactions within the microbiota and their potential relevance in human health and disease: a short review
Published in Gut Microbes, 2022
Alexia Lapiere, Mathias L Richard
QS appears to be a complex, intricate system of communication involving a wide range of actors; however, the existence of QS inhibitors further complicates this system. Indeed, if QSMs are involved in bacterial-fungal metabolic communication, quorum quencher molecules from bacteria and fungi are able to interfere with the QS dialog. Various mechanisms of quorum quenching have been reported: inhibition of QS molecule synthesis, inhibition of QS molecule-receptor interaction and modification/degradation of QSMs.54 Recently, a study demonstrated a QS inhibitory molecule produced by kefir fungi against pathogenic gut bacteria:55Kluyveromyces marxianus is a predominant yeast found in kefir, a fermented beverage considered a probiotic food with therapeutic benefits for health. K. marxianus is able to secrete high quantities of tryptophol, which has shown an inhibitory effect on the biofilm production of Vibrio cholerae, a deleterious bacterium in the human gut. Through tryptophol secretion, K. marxianus interferes with V. cholerae autoinducer CAI-1-driven QS communication, resulting in decreased biofilm production and thus reduced virulence. To date, this study is the only one demonstrating a bacterial-fungal interaction involving quorum quenching in the human ecosystem. Other bacterial-fungal quorum quenching has been observed in environmental ecosystems (soil, mycorrhiza, and water), i.e., root-associated fungi, belonging to the Ascomycota and Basidiomycota lineages, are able to secrete lactonase, an enzyme that deteriorates the bacterial N-acyl homoserine lactone QSM.56 It is thought that fungi and bacteria found in human microbiological niches could be able to secrete quorum quenching lactonases, considering that they have evolved together in the same ecosystem and developed sophisticated interkingdom interactions, including QS. However, no study has explored this hypothesis at this time.