Phosphorus is one of the three macronutrients that are essential for plant growth and development. Inorganic phosphorus (P), which can make up to 70% of the total P content in soils, can exist in calcium-, aluminum-, or iron-complexed forms that are unavailable for plant use. As a result, mineral phosphorus, P 2 O 5 , is often used as a fertilizer to supplement the nutrient for crop growth. To reduce the addition of mineral phosphorus to agricultural soils, research in naturally occurring phosphate-solubilizing microorganisms has been conducted for decades. This study found bacteria that solubilized phosphate at very high rates. The most efficient of the bacteria presented in this paper, Pantoea sp. Pot1, can solubilize tricalcium phosphate (Ca 3 (PO 4 ) 2 ) at a rate of 956 mg L -1 . This bacteria produces a variety of organic acids, including acetic, gluconic, formic, and propionic acids. Greenhouse experiments demonstrated that tomato plants with soil systems inoculated with Pantoea sp. Pot1 incorporated more P and produced much higher biomass weights than those plants without any added bacteria.

Agricultural productivity relies on synthetic nitrogen fertilizers, yet half of that reactive nitrogen is lost to the environment. There is an urgent need for alternative nitrogen solutions to reduce the water pollution, ozone depletion, atmospheric particulate formation, and global greenhouse gas emissions associated with synthetic nitrogen fertilizer use. One such solution is biological nitrogen fixation (BNF), a component of the complex natural nitrogen cycle. BNF application to commercial agriculture is currently limited by fertilizer use and plant type. This paper describes the identification, development, and deployment of the first microbial product optimized using synthetic biology tools to enable BNF for corn (Zea mays) in fertilized fields, demonstrating the successful, safe commercialization of root-associated diazotrophs and realizing the potential of BNF to replace and reduce synthetic nitrogen fertilizer use in production agriculture. Derived from a wild nitrogen-fixing microbe isolated from agricultural soils, Klebsiella variicola 137-1036 (“Kv137-1036”) retains the capacity of the parent strain to colonize corn roots while increasing nitrogen fixation activity 122-fold in nitrogen-rich environments. This technical milestone was then commercialized in less than half of the time of a traditional biological product, with robust biosafety evaluations and product formulations contributing to consumer confidence and ease of use. Tested in multi-year, multi-site field trial experiments throughout the U.S. Corn Belt, fields grown with Kv137-1036 exhibited both higher yields (0.35 ± 0.092 t/ha ± SE or 5.2 ± 1.4 bushels/acre ± SE) and reduced within-field yield variance by 25% in 2018 and 8% in 2019 compared to fields fertilized with synthetic nitrogen fertilizers alone. These results demonstrate the capacity of a broad-acre BNF product to fix nitrogen for corn in field conditions with reliable agronomic benefits.

Employing concepts from physics, chemistry and bioengineering, 'learning-by-building' approaches are becoming increasingly popular in the life sciences, especially with researchers who are attempting to engineer cellular life from scratch. The SynCell2020/21 conference brought together researchers from different disciplines to highlight progress in this field, including areas where synthetic cells are having socioeconomic and technological impact. Conference participants also identified the challenges involved in designing, manipulating and creating synthetic cells with hierarchical organization and function. A key conclusion is the need to build an international and interdisciplinary research community through enhanced communication, resource-sharing, and educational initiatives.

Background Efficient cell-free protein expression from linear DNA templates has remained a challenge primarily due to template degradation. In addition, the yields of transcription in cell-free systems lag behind transcriptional efficiency of live cells. Most commonly used in vitro translation systems utilize T7 RNA polymerase, which is also the enzyme included in many commercial kits. Results Here we present characterization of a variant of T7 RNA polymerase promoter that acts to significantly increase the yields of gene expression within in vitro systems. We have demonstrated that T7Max increases the yield of translation in many types of commonly used in vitro protein expression systems. We also demonstrated increased protein expression yields from linear templates, allowing the use of T7Max driven expression from linear templates. Conclusions The modified promoter, termed T7Max, recruits standard T7 RNA polymerase, so no protein engineering is needed to take advantage of this method. This technique could be used with any T7 RNA polymerase- based in vitro protein expression system.