Industrial microbiology

  • Article
    | Open Access

    Brassinolide (BL) is one of the most active compounds among phytohormone brassinosteroids (BRs) and can be used for plant growth and development regulation. Here, the authors report the construction of an artificial pathway in baker’s yeast for scalable production of 24-epi-ergosterol, a precursor for BL semi-synthesis.

    • Yiqi Jiang
    • , Zhijiao Sun
    •  & Lirong Yang
  • Article
    | Open Access

    Marine ecosystems are dominated by microbial communities. Inspired by the photoelectric conversion feature of the marine ecosystems, the authors design a four-species microbial community to mimic primary producer, primary degrader, and ultimate consumers, and show its ability to convert light into electricity for over one month.

    • Huawei Zhu
    • , Liru Xu
    •  & Yin Li
  • Article
    | Open Access

    CRISPR gene activation and inhibition has become a powerful synthetic tool for influencing the expression of native genes for foundational studies, cellular reprograming, and metabolic engineering. Here the authors demonstrate near leak-free, inducible expression of a polycistronic array containing up to 24 gRNAs from two orthogonal CRISPR/Cas systems.

    • William M. Shaw
    • , Lucie Studená
    •  & Rodrigo Ledesma-Amaro
  • Article
    | Open Access

    Gene dosage-based expression upregulation suffers from instability and random gene integration. Here, the authors report HapAmp, a method that uses haploinsufficiency as evolutionary force to drive in vivo gene amplification, and demonstrate its applications in protein and biochemical production in yeast.

    • Bingyin Peng
    • , Lygie Esquirol
    •  & Claudia E. Vickers
  • Article
    | Open Access

    Domesticated industrial yeast strains are sterile, which hampers to breed strains with novel properties. Here, the authors employ the genetics paradigm return-to-growth to induce genome wide recombination in two sterile polyploid industrial yeasts and identify clones with superior biotechnological traits.

    • Simone Mozzachiodi
    • , Kristoffer Krogerus
    •  & Gianni Liti
  • Article
    | Open Access

    Microbial communities are responsible for biological wastewater treatment. Here, Dueholm et al. generate more than 5 million high-quality, full-length 16S rRNA gene sequences from wastewater treatment plants across the world to construct a database with a comprehensive taxonomy, providing insights into diversity and function of these microbial communities.

    • Morten Kam Dahl Dueholm
    • , Marta Nierychlo
    •  & Per Halkjær Nielsen
  • Article
    | Open Access

    Microbial production of oleochemicals involves strategies of expressing thioesterase to narrow the substrate pool for the termination enzyme at the expense of one ATP. Here, the authors developed an alternative energy-efficient strategy to use of an acyl-ACP transacylase to produce medium chain oleochemicals in E. coli.

    • Qiang Yan
    • , William T. Cordell
    •  & Brian F. Pfleger
  • Article
    | Open Access

    Here, the authors characterize the gut microbiome fermentation properties and therapeutic potential of chemically diverse synthetic glycans (SGs), showing they promote specific shifts in taxonomic and metabolite profiles, and exhibit therapeutic benefits in mouse models of colonic inflammation, together implying SGs as a potential avenue to treat disease by modulating the composition and metabolites produced by the gut microbiome.

    • Andrew C. Tolonen
    • , Nicholas Beauchemin
    •  & Johan E. T. van Hylckama Vlieg
  • Article
    | Open Access

    Growth limitation caused by mutual shading and the high harvest cost hamper algal biofuel production. Here, the authors overcome these two problems by designing a semi-continuous algal cultivation system and an aggregation-based sedimentation strategy to achieve high levels production of biomass and limonene.

    • Bin Long
    • , Bart Fischer
    •  & Joshua S. Yuan
  • Article
    | Open Access

    The testing of engineered enzymes represents a bottleneck. Here the authors report a screening method combining microfluidics and mass spectrometry, to map the catalysis of a mutated enzyme, characterise the range of products generated and recover the sequences of variants with desired activities.

    • Linfeng Xu
    • , Kai-Chun Chang
    •  & Adam R. Abate
  • Article
    | Open Access

    Returning from Mars to Earth requires propellant. The authors propose a biotechnology-enabled in situ resource utilization (bioISRU) process to produce a Mars specific rocket propellant, 2,3-butanediol, using cyanobacteria and engineered E. coli, with lower payload mass and energy usage compared to chemical ISRU strategies.

    • Nicholas S. Kruyer
    • , Matthew J. Realff
    •  & Pamela Peralta-Yahya
  • Article
    | Open Access

    Here, the authors engineer microbial production of muscle titin fibers with highly desirable mechanical properties and provide structural analyses that explain the molecular mechanisms underlying high performance of this polymer with potential uses in biomedicine and textile industries, among others.

    • Christopher H. Bowen
    • , Cameron J. Sargent
    •  & Fuzhong Zhang
  • Article
    | Open Access

    Esters can be used as fuels and specialty chemicals for food flavoring, cosmetic and pharmaceutical industries. Here, the authors systematically engineer clostridia, including discovery and deletion of prophages to increase strain stability, for the production of butyl acetate and butyl butyrate from corn stover at low cost.

    • Jun Feng
    • , Jie Zhang
    •  & Yi Wang
  • Article
    | Open Access

    3-Hydroxypropionic acid (3HP) is an important platform chemical. Here, the authors engineer Halomonas bluephagenesis by deleting newly identified degradation pathway and balancing redox state to achieve high level production of 3HP and its copolymer under open and unsterile conditions.

    • Xiao-Ran Jiang
    • , Xu Yan
    •  & Guo-Qiang Chen
  • Article
    | Open Access

    Industrial sugarcane ethanol fermentations are accomplished by a microbial community dominated by S. cerevisiae and co-occurring bacteria. Here, the authors investigate how microbial community composition contributes to community function and reveal the role of acetaldehyde in improving yeast growth rate and ethanol production.

    • Felipe Senne de Oliveira Lino
    • , Djordje Bajic
    •  & Morten Otto Alexander Sommer
  • Article
    | Open Access

    The cost and complexity of whole genome sequencing limits its use in identifying and validating sequences used for genetic engineering and synthetic biology. Here the authors present Prymetime, an integrated workflow to sequence engineered strains and identify engineering in metagenomes.

    • Joseph H. Collins
    • , Kevin W. Keating
    •  & Eric M. Young
  • Article
    | Open Access

    Chondroitin sulfate (CS) is a type of sulfated glycosaminoglycan that is manufactured by extraction from animal tissues for the treatment of osteoarthritis and in drug delivery applications. Here, the authors report the development of single microbial cell factories capable of compete, one-step biosynthesis of animal-free CS production in E. coli.

    • Abinaya Badri
    • , Asher Williams
    •  & Mattheos A. G. Koffas
  • Article
    | Open Access

    Direct cloning of biosynthetic gene clusters is difficult due to their size and repetitive nature. Here, the authors present CAPTURE, which uses Cas12a and in vivo Cre-lox recombination for efficient cloning of gene clusters up to 113 kb, and demonstrate how this method can be used for large-scale discovery of novel natural products.

    • Behnam Enghiad
    • , Chunshuai Huang
    •  & Huimin Zhao
  • Article
    | Open Access

    Short-chain primary amines (SCPAs) are industrially important compounds that are commonly produced under harsh synthetic conditions. Here, the authors report a combination of retrobiosynthesis and precursor selection step for design of biosynthetic pathways leading to production of SCPAs, using valine decarboxylase-expressing Escherichia coli strains.

    • Dong In Kim
    • , Tong Un Chae
    •  & Sang Yup Lee
  • Article
    | Open Access

    The development of techniques capable of orchestrating the assembly of living cells into multicellular ensembles with synergistic and function is challenge. Here, the authors construct algal or algal/bacterial cells-based core shell-like structure based on aqueous two-phase system for synergic photosynthetic H2 production.

    • Zhijun Xu
    • , Shengliang Wang
    •  & Stephen Mann
  • Article
    | Open Access

    The structural programmability and functionality of peptide materials can be leverage for various next-generation devices such as non-volatile memories. The authors report a proton-coupled mechanism in tyrosine-rich peptides for realizing multimodal memory devices.

    • Min-Kyu Song
    • , Seok Daniel Namgung
    •  & Jang-Yeon Kwon
  • Article
    | Open Access

    Rare earth elements are used in electronics, but increase in demand could lead to low supply. Here the authors conduct experiments on the International Space Station and show microbes can extract rare elements from rocks at low gravity, a finding that could extend mining potential to other planets.

    • Charles S. Cockell
    • , Rosa Santomartino
    •  & René Demets
  • Article
    | Open Access

    An imbalance between cell growth and bioproduction of engineered microbes often reduces production efficiency. Here, the authors report genetic code expansion-based cell growth and biosynthesis balance engineering to achieve high levels production of N-acetylglucosamine in E. coli and N-acetylneuraminic acid in B. subtilis.

    • Rongzhen Tian
    • , Yanfeng Liu
    •  & Jian Chen
  • Article
    | Open Access

    Transcriptional biosensors represent powerful tools for the screening of vast strain libraries, but the broad ligand specificity of some transcriptional regulators (TRs) can prohibit such applications. Here authors present the engineering of a LysG-based biosensor with a focused ligand specificity to isolate L-histidine-producing strains.

    • Dennis Della Corte
    • , Hugo L. van Beek
    •  & Jan Marienhagen
  • Article
    | Open Access

    Successful application of microbial community for bioproduction relies on the selection of appropriate heterotroph and phototroph partners. Here, the authors construct community metabolic models to guide strain selection and experimentally validate metabolic exchanges that sustain the heterotrophs in minimal media.

    • Cristal Zuñiga
    • , Tingting Li
    •  & Karsten Zengler
  • Article
    | Open Access

    Bioproduction of hyaluronan needs increases in yield and greater diversity of the molecular weights. Here, the author increases hyaluronan production and diversifies the molecular weights through engineering the hyaluronan biosynthesis pathway and disruption of Corynebacterium glutamicum encapsulation caused by secreted hyaluronan.

    • Yang Wang
    • , Litao Hu
    •  & Zhen Kang
  • Article
    | Open Access

    Manipulation of genes controlling microbial shapes can affect bio-production. Here, the authors employ an optogenetic method to realize dynamic morphological engineering of E. coli replication and division and show the increased production of acetoin and poly(lactate-co-3-hydroxybutyrate).

    • Qiang Ding
    • , Danlei Ma
    •  & Xiulai Chen
  • Article
    | Open Access

    Fermentation parameters of industrial processes are often not the ideal growth conditions for industrial microbes. Here, the authors reveal that young genes are more responsive to environmental stress than ancient genes using a new gene age assignment method and provide targeted genes for metabolic engineering.

    • Tyler W. Doughty
    • , Iván Domenzain
    •  & John P. Morrissey
  • Article
    | Open Access

    Malate dehydrogenase (MDH) is one of the key enzymes for succinic acid (SA) bioproduction. Here, the authors report biochemical and structural analyses of various MDHs to reveal amino acids influencing the specific activity and susceptibility to substrate inhibition, and achieve industrial-level SA production.

    • Jung Ho Ahn
    • , Hogyun Seo
    •  & Sang Yup Lee
  • Article
    | Open Access

    Corn fiber is a difficult feedstock to utilize due to its recalcitrant hemicellulose. Here, the authors characterize the recalcitrant structures, isolate a new bacterium to consume the hemicellulose, identify its enzymes, and show the benefit with increased conversion of corn fiber to ethanol.

    • Dhananjay Beri
    • , William S. York
    •  & Christopher D. Herring
  • Article
    | Open Access

    Combining genome mining and heterologous expression in a genetically tractable host can lead to bioactive natural products discovery and production. Here, the authors employ this strategy for new decalin-containing diterpenoid pyrenes production by expressing native, extended, and shunt pathways in Aspergillus oryzae.

    • Kento Tsukada
    • , Shono Shinki
    •  & Teigo Asai
  • Article
    | Open Access

    Developing cyanobacteria as CO2-neutral cell factories relies on the knowledge of the regulation mechanisms for growth and metabolism. Here, the authors develop an inducible CRISPRi gene repression library in Synechocystis sp. PCC 6803 and screens genes potentially affecting growth and L-lactate tolerance and production.

    • Lun Yao
    • , Kiyan Shabestary
    •  & Elton P. Hudson
  • Article
    | Open Access

    Biosynthetic mechanism for the type 2 diabetes treatment drug acarbose is not fully revealed. Here, the authors show that shunt pathways and inefficient amino-deoxyhexose biosynthesis lead to 1-epi-valienol and valienol accumulation, and minimizing the flux to these shunt products can increase acarbose titer in Actinoplanes species.

    • Qinqin Zhao
    • , Yuchang Luo
    •  & Zixin Deng
  • Article
    | Open Access

    Aspergillus fungi classified within the section Flavi include harmful and beneficial species. Here, Kjærbølling et al. analyse the genomes of 23 Flavi species, showing high genetic diversity and potential for synthesis of over 13,700 CAZymes and 1600 secondary metabolites.

    • Inge Kjærbølling
    • , Tammi Vesth
    •  & Mikael R. Andersen
  • Article
    | Open Access

    Existing efforts have been focused on one of the elements in the automation of the design, build, test, and learn (DBTL) cycle for biosystems design. Here, the authors integrate a robotic system with machine learning algorithms to fully automate the DBTL cycle and apply it in optimizing the lycopene biosynthetic pathway.

    • Mohammad HamediRad
    • , Ran Chao
    •  & Huimin Zhao
  • Article
    | Open Access

    Existing heavy metal bioremediation systems are mainly based on plants, which require long growing time in specific conditions. Here, the authors mimic the characteristics of plant hyperaccumulators to engineer more tractable baker’s yeast and achieve 10–100-fold higher accumulation of chromium, arsenic, or cadmium.

    • George L. Sun
    • , Erin. E. Reynolds
    •  & Angela M. Belcher
  • Article
    | Open Access

    Microbial production of aromatic amino acid (AAA)-derived chemicals remains an outstanding metabolic engineering challenge. Here, the authors engineer baker’s yeast for high levels p-coumaric acid production by rewiring the central carbon metabolism and channeling more flux to the AAA biosynthetic pathway.

    • Quanli Liu
    • , Tao Yu
    •  & Yun Chen
  • Article
    | Open Access

    Power densities of existing microbial biophotovoltaics (BPV) are low and unendurable. Here, the authors develop a BPV based on d-lactate mediated microbial consortium, which can generate an average power density of 135 mW·m−2 for over 40 days in a spatial-temporal separation setup with medium replenishment.

    • Huawei Zhu
    • , Hengkai Meng
    •  & Yin Li