Team:NAWI-Graz/Description

Team:NAWI-Graz - 2021.igem.org

Team:NAWI-Graz


Project Description


"A journey of a thousand miles begins with a single step"


Outlining The Problem


Without Phosphorus, no plant would grow. And since modern agriculture is demanding a lot more from soils than it can naturally handle, fertilizers have to be added to the soil to support the expected amount of crops yield. While European phosphate fertilizer consumption has gone down, even though we have seen a growth rate in total trade values on average, of 2.5 % annually for agricultural products in the European Union between 2002 and 2019. [1] [2] On the other hand the use of phosphate fertilizer in Asian countries has more than doubled (relative to the amount of people) over the last 40 years. [3] The phosphorus problem spans itself a lot further than the scientific aspects.


Origins


The modern world we live in has taught us to be creative in coping with the growing scarcity of natural resources, and to keep making fertilizers that make even the most exotic plants grow in foreign lands and different soils. To better understand this problem we need to understand what makes phosphorus so special in developing a strategy for the handling of resources that might run out.

The three main parts are being looked at, when analysing the future availability of natural resources.

Reserves can be accessed with available technology under socio-economically acceptable conditions.

Resources are known deposits of the commodity, but the economic viability to access them is just not there yet.

Through constant exploration and geological reasoning, geopotential summarizes all reserves and resources of the future but unknown at the present.

There are also three groups of deposits of phosphorus bearing minerals (phosphates), Insular, Igneous and Sedimentary. Insular, the accumulation of bird and bat excrement may be viewed as a renewable resource, but since this group only accounts for 0.6% of the world phosphate production and the deposits are nearly exhausted. The other types of deposits are considered as non-renewable. With this information and the absence of a phosphorus-cycle, compared to the Nitrification in the soil, leaves without a reasonable way to recycle phosphorus, yet. [4]

In 2010, the production was 83% from sedimentary and 17% from igneous deposits, while 66% of the phosphorus bearing minerals were mined in Morocco, China and the USA. [5] Since phosphorus is seen as a low price commodity shown in an example by R. Scholz and F.W. Wellmer 2013, doubling the price of phosphate would result in no socio-economic change for the individual. Most poor smallholder farmers' income is greatly influenced by small price increases. And since most scarce natural resources in history have gone through a price increase as soon as they become scarce, this problem forms a perfect breeding ground for social inequality.


The Socioeconomics


Morocco is the largest producer of phosphate in the world and holds about 75% of the world´s estimated reserves. [6] The revenue generated from phosphate and its derivatives is approximately $5.9 billion. [7] Phosphate is mined with heavy equipment, creates a large amount of noise and swirls a lot of dust containing Fluor, which is toxic. Reports say that safety equipment would rarely be available and the implications of decade long neglect of the set standards, shows frightening effects on the health of the workers. [8]

The phosphate monopoly in Morocco is held by the state owned company OCP, which employs around 20.000 people. [9] After the riots broke out in one of these mining regions a fair amount of attention was drawn to the phosphate mines in Morocco and the existing working conditions. The protest was not intended to demand a better working environment for the miners, but instead OCP issued a list of a few hundred jobs and more than 30.000 young Moroccans applied for. With an unemployment rate of 33 % among Moroccans aged below 35 it was enough social tension to spark a riot to get jobs at OCP. [10]

Phosphorus is not only a finite essential resource that allows us to sustain food security for 89 % of the world population, while still leaving 820 million people undernourished. It also creates jobs for people that are desperate for employment, but the way it is mined makes them, sometimes deathly sick. And if the price of phosphate goes up due to better safety standards in the mines, the only people feeling the price increase are small scale farmers, buying fertilizer in comparatively small quantities. All of this and more is reason for us, the IGem NAWI-Graz Team 2021 “Phos4us” to think of better ways to prolong or better the lifecycle of phosphorus in soils.

To support the growing human population, the enhancement of sufficient food supply e.g., with crops such as wheat, maize or sugarcane is absolutely inevitable. Modern agricultural methods mainly rely on the excessive use of fertilizers such as phosphate, which is a finite resource. Without phosphate containing fertilizers, humanity would only be able to produce half of the current global food demand. The current phosphate consumption rate of mined phosphate containing rock will empty our worldwide reserves in about 100 years. After that, industrial agriculture as we know it today will not be possible anymore if alternatives ways in phosphate application or production are not applied soon.[12]

Additionally, overuse of phosphate-containing fertilizers can lead to its accumulation in the soil, until heavy precipitation or excessive irrigation bring it up from the soil to the surface. Soluble phosphate gets washed out from the soil which results in the introduction into aquatic ecosystems. Widespread environmental problems such as phosphate surplus in these habitats can cause excessive plant growth, algae blooming and over all a loss in biodiversity. [13] [14]

The Outline Of The Possible Solution


Since these problems could potentially cause much harm for future generations as well as our planet, and we wanted to work on a project that serves a greater cause, the iGEM Nawi Graz 2021 Team decided to search for a possible solution for them. We put our efforts in investigating a possibility to decrease the load of needed phosphate fertilizers to be able to use our natural occurring reserves for longer than the predicted time, until other possibilities are developed. Particularly unfortunate is the fact that the majority of inorganic phosphate used in fertilizers gets immobilized within the soil and is therefore unavailable for plants. A potential remedy against this waste of fertilizer are so called phosphate solubilizing bacteria such as Pantoea agglomerans, Microbacterium laevaniformans and Pseudomonas putida which are capable of solubilizing inorganic phosphorus and therefore providing plants with the nutrient in a way they can take up.

Problem Description



[15]
https://en.wikipedia.org/wiki/Phosphate_solubilizing_bacteria

Taking part in the iGEM competition and using Synthetic biology concepts we decided to investigate the possibility of using recombinant bacteria to detect surplus phosphate concentrations and then further on recruiting natural in the soil occurring phosphate solubilizing bacteria to proliferate and increase their phosphate solubilizing activity.



The Goals


We tried to engineer a phosphate sensing device that is able to detect phosphate within the environment which leads to the production of 3-oxohexanoyl-homoserine lactone (3OC6HSL)[16], a small signaling molecule involved in quorum sensing (QS) activities. Since QS is used by many bacterial species to coordinate population behavior such as biofilm formation and invoking cell growth, it could also lead to an increase inorganic phosphate solubilization by PSBs.[17]
The prototype of the device (containing green fluorescent protein as a reporter instead of the 3OC6HSL producing enzyme) was constructed and characterized within the model organism E. coli T10 although we are convinced that for actual application, other natural in the soil occuring bacteria (e.g., Pseudomonas spp.) would be a better host organism within that habitat.

Due to the global SARS-CoV2 pandemic we only had access to the laboratory of the University of Graz for a limited amount of time (about 3 Months), so we decided to focus our experimental efforts on the realization of the biosensor. To honor the spirit of the iGEM competition of collaboration especially with the usage of parts, other teams developed, we choose to utilize an already existing 3OC6HSL receiver (BBa_T9002) to test our phosphate sensing device. Future challenges will imply to investigate its actual ability to stimulate growth or phosphorus solubilizing abilities in artificial or natural microbial communities of PSBs.

References


  • [1] ‘Extra-EU Trade in Agricultural Goods - Statistics Explained’. Accessed 21 January 2021. https://ec.europa.eu/eurostat/statistics-explained/index.php/Extra-EU_trade_in_agricultural_goods#Agricultural_products:_3_main_groups.
  • [2] Hatim, Yahia. ‘Morocco’s Automotive Exports Exceed Revenue of Phosphate Exports’. Morocco World News (blog), 10 November 2020. https://www.moroccoworldnews.com/2020/11/325388/moroccos-automotive-exports-exceed-revenue-of-phosphate-exports/.
  • [3] Jasinski, Stephen M. ‘Phosphate Rock’. Mineral Commodity Summaries, 2011, 122–23.
  • [4] Karam, Souhail. ‘New Riots in Moroccan Phosphate Region over Jobs’. Reuters, 7 July 2011. https://www.reuters.com/article/morocco-riots-phosphates-idAFLDE7661ME20110707.
  • [5] Mennig, Daniel. ‘Umwelt Und Verkehr - Schädlicher Phosphat-Abbau: Arbeiter Leiden Für Unseren Dünger - Kassensturz Espresso - SRF’. Accessed 20 January 2021. https://www.srf.ch/sendungen/kassensturz-espresso/themen/umwelt-und-verkehr/schaedlicher-phosphat-abbau-arbeiter-leiden-fuer-unseren-duenger.
  • [6] ‘Mining Industry of Morocco’. In Wikipedia, 7 January 2021. https://en.wikipedia.org/w/index.php?title=Mining_industry_of_Morocco&oldid=998937342.
  • [7] Our World in Data. ‘Phosphate Fertilizer Consumption’. Accessed 21 January 2021. https://ourworldindata.org/grapher/phosphate-fertilizer-consumption.
  • [8] Roser, Max, and Hannah Ritchie. ‘Hunger and Undernourishment’. Our World in Data, 8 October 2013. https://ourworldindata.org/hunger-and-undernourishment.
  • [9] Scholz, Roland W., and Friedrich-Wilhelm Wellmer. ‘Approaching a Dynamic View on the Availability of Mineral Resources: What We May Learn from the Case of Phosphorus?’ Global Environmental Change 23, no. 1 (1 February 2013): 11–27. https://doi.org/10.1016/j.gloenvcha.2012.10.013.
  • [10] White, Natasha. ‘Toxic Shadow: Phosphate Miners in Morocco Fear They Pay a High Price | Natasha White’. the Guardian, 16 December 2015. http://www.theguardian.com/global-development/2015/dec/16/toxic-shadow-phosphate-miners-morocco-fear-they-pay-high-price.
  • [12] https://www.theguardian.com/environment/2019/sep/06/phosphate-fertiliser-crisis-threatens-world-food-supply (12.03.2020)
  • [13] #SL 261, 2018-08-13, Shober, Amy L, Gulf Coast REC, Department of Soil and Water Sciences
  • [14] PNAS July 19, 2005 102 (29) 10002-10005; https://doi.org/10.1073/pnas.0503959102
  • [15] https://en.wikipedia.org/wiki/Phosphate_solubilizing_bacteria (22.03.2020)
  • [16] https://parts.igem.org/3OC6HSL
  • [17] Vittorio Venturi, Regulation of quorum sensing in Pseudomonas, FEMS Microbiology Reviews, Volume 30, Issue 2, March 2006, Pages 274–291, https://doi.org/10.1111/j.1574-6976.2005.00012.x