Boost Your Biological Formulations with Clariant's Advanced Co-formulants and Adjuvants

In response to growing demand for sustainable agricultural practices, integrated crop management, and increasing regulatory pressures, the biologicals market is experiencing significant growth. Biological products encompass a wide array of natural components, with microbials representing the most commercially relevant segment. These products serve dual roles: as biostimulants, they enhance plant nutrient uptake and promote plant health; and as biocontrol agents, when bacteria, fungi, viruses, and their metabolites target specific pests or diseases [1; 2]. Despite their potential, the efficacy of biologicals often falls short compared to conventional chemical alternatives. As the biologicals market continues to expand rapidly, new solutions are required that enable biological products to deliver robust performance. 

Clariant is committed to unlocking the full potential of biological products. We are leveraging our extensive expertise in specialty chemicals to develop co-formulants for microbe-based formulations and novel adjuvant technologies to boost their efficacy. In the following, we highlight our research and application capabilities as well as our dedicated portfolio for biologicals, which allows us to significantly enhance the performance of biologicals close to the level of conventional products. 

Comprehensive testing suite for microbials

Our approach to enhancing biological formulations follows a multiple step process (Figure 1). It begins with the screening of suitable components using biocompatibility assays. This is followed by formulation optimization, including the selection of tank-mix partners, formulation design, stability and application testing under realistic spray conditions, allowing the refinement of formulations for specific application conditions. These tests help to tailor formulations to specific application challenges, such as varying abiotic factors or rainfastness. The final validation stage involves greenhouse and field trials to evaluate the effectiveness of the formulations under both controlled and real-world crop conditions.

Given that microbial viability is critical, all co-formulants and tank-mix partners must be biocompatible. Clariant has developed a customized high-throughput methodology that employs an indirect fluorescence assay to measure metabolic activity. This fully digitalized and automated approach enables rapid large-scale biocompatibility testing of formulation ingredients across a range of relevant microorganisms and concentrations to simulate both tank-mix and in-can scenarios.

Figure 1: Overview of Clariant’s capabilities to design biological formulations and optimize their application.

Toolbox for biological formulations and formulation example

Leveraging our customized high-throughput biocompatibility assay, we have developed a formulator’s toolbox comprising a broad range of biocompatible ingredients for designing biological formulations (Table 1). It includes dispersing agents, emulsifiers, wetting agents, protective polymers and utility modifiers, providing flexibility to formulators to support their specific performance and regulatory requirements. 

Table 1: Clariant’s toolbox of biocompatible co-formulants and adjuvants identified by cell viability assay with relevant microorganisms.

The example shown in Table 2 illustrates how our biologicals toolbox can be used to optimize a formulation. Dry formulations are commonly employed to extend microbial shelf-life, particularly fungal conidia or spores. However, they often exhibit poor wettability and dispersibility, resulting in floating or sedimentation in spray solutions - challenges well documented in recent publications [3, 4]. 

We selected the genus Trichoderma, a widely used fungus in biofungicides and plant growth-promoting products, typically formulated as a wettable powder (WP). Using our biocompatibility data, we developed an optimized WP formulation displayed in Table 2. Dispersogen™ SI, was chosen as a wetting and dispersing agent. It is fully compatible with Trichoderma spp. and formulation performance can be further enhanced in combination with Hostapon TPHC. The resulting guide formulation meets established stability criteria and regulatory specifications for biological products, demonstrating improved wettability and suspensibility.

Table 2: Guide recipe for WP formulation of Trichoderma spp. including wettability, suspensibility and wet sieve test results. 

Although dry formulations are the leading product type for biologicals, liquid formulations such as oil dispersions (OD) are becoming more popular as they offer easier handling and better convenience to growers. Clariant’s formulation toolbox also provides good solutions for liquid formulations, such as Emulsogen™ ELO 200, which is a high performing emulsifier and dispersing agent for vegetable oil-based systems.

New adjuvants to boost foliar applied biological formulations

Well-designed formulations and the use of specialized adjuvants can help to overcome inconsistent performance of biologicals. While traditional adjuvants often fail with microbial actives limiting their effectiveness [5], we have developed Synergen™ Guard 100, specifically designed to boost the performance of biological formulations and demonstrated that Synergen GL 5, also provides significant benefits for these products. 

Synergen™ Guard 100 – Performance booster and rainfastness agent

Synergen Guard 100 is a natural wax-based nano-emulsion designed to boost biologicals. It shows excellent biocompatibility as confirmed by both our high-throughput viability assay as well as the well-established disk diffusion tests, where no effect on the growth of the selection of different tested microorganisms was observed (Figure 2). 

Figure 2: Biocompatibility of Synergen™ Guard 100 with relevant microorganisms measured by cell viability assay and disk diffusion test results. 

Coverage and wetting of the leaf surface are essential for effective disease management with biologicals. We have carried out coverage and deposition tests in our spray chamber using a commercially available B. amyloliquefaciens formulation with typical nozzle types, water volumes and use rates indicated on the label. When applied as tank-mix adjuvant with the microbial formulation, the use of Synergen Guard 100 significantly increased the spray deposition compared to the treatments without adjuvant. Our coverage measurements showed a 2.5-fold increase on grape leaves with Synergen Guard 100 compared to non-adjuvanted controls (Figure 3). 

Figure 3: Spray coverage measurement on grape leaves with commercial B. amyloliquefaciens formulation (4L/ha in 400L/ha) without adjuvant (left) and with 1% Synergen Guard 100 (right). 

Another important parameter for the performance of biologicals is rainfastness. For the rainfastness study we used spray deposits of dried 5 µL droplets on parafilm assessing CFU after rain simulation (1mL rainwater pipetted) as well as examining the spray deposit morphology on leaf cuticles using electron microscopy after water dipping. In both cases a commercial B. amyloliquefaciens formulation was used. 

Figure 4 shows a dried deposit of spray solutions containing Synergen™ Guard 100 applied on leaf cuticles before and after the dipping test. The microscopy pictures show that the deposit was well maintained even after immersion in water for 2min due to the formation of a stable nanofilm. Figure 5 illustrates the results of the rainfastness study on parafilm using CFU counting, which confirms our findings from the deposit morphology assessment. Treatments with Synergen Guard 100 maintained bacterial CFU (colony forming units) after simulated rain, compared to a reduction of 1,2 log CFU/ml or only 6.3% retention of the control without the addition of the adjuvant (Figure 4) and clearly demonstrates that Synergen Guard 100 strongly improves rainfastness.

Figure 4: Scanning electron microscopy of spray deposit with Synergen Guard 100 before and after rain simulation. 

Figure 5: Bacteria count of dried spray droplets applied on parafilm (21.5°C, 40.6%RH for 3h) with B. amyloliquefacies formulation (4L/ha in 200L/ha water) and different Synergen Guard 100 concentrations with rain simulation.

Finally, we have studied the performance of a commercial B. bassiana formulation for whitefly control in greenhouse trials with Synergen Guard 100 as whitefly poses a substantial threat to both greenhouse and field crop production globally [6]. The results in Table 3 demonstrate that the levels of control significantly improved to above 50% with the addition of 0.5% adjuvant, compared to below 30% without adjuvant. This means that the efficacy of whitefly control doubled when the bioinsecticide was applied together with Synergen Guard 100 in the tank mix, matching the performance of a conventional insecticide. 

Table 3: Greenhouse results of bioinsecticide with and without Synergen Guard 100 for whitefly nymph control.

Synergen™ GL 5 – label free enhancer for biofungicides

Synergen™ GL 5: a polyglycerol ester-based adjuvant without hazardous labelling and shows good compatibility with microorganisms as exemplified by our biocompatibility studies (see also table 1). 

As shown in Figure 6, Synergen GL 5 is improving coverage as well as reducing coffee ring formation which typically leads to better performance of biocontrol products. Greenhouse trials with a commercial Bacillus formulation for downy mildew control were conducted to prove the positive effect on biological efficacy using the adjuvant Synergen GL 5. As shown in Figure 6, Synergen GL 5 enhances efficacy of the tested biofungicide. Treatments using 0.25% of Synergen GL 5 as tank-mix adjuvant improved downy mildew control on wine leaves from around 68% to 80% compared to the application of the biofungicide alone. 

Figure 6: Greenhouse efficacy of commercial Bacillus formulation with and without 0.25% of Synergen GL 5 for downy mildew control on wine leaves and microscopy images of 0.5 µl dried spray droplets.

Conclusion

As the biologicals market continues to evolve, Clariant remains at the forefront of innovation with specialized co-formulants and adjuvants that address key formulation challenges. Our comprehensive approach - from biocompatibility screening to field validation - allows us to develop solutions that enhance the performance of biological products. Our latest innovations like Synergen Guard 100 and Synergen GL 5 exemplify our commitment to enhancing efficacy, stability, and sustainability in agricultural solutions. By partnering with Clariant, formulators gain access to unique expertise that transforms promising biological actives into market-ready products that meet tomorrow's agricultural demands.

™ = trademark of Clariant

References:

1. Pérez-García A, Romero D, de Vicente A. Plant protection and growth stimulation by microorganisms: biotechnological applications of Bacilli in agriculture. Curr Opin Biotechnol. 2011 Apr;22(2):187-93. Review.

2. Montesinos E. Development, registration and commercialization of microbial pesticides for plant protection. Int Microbiol (2003) 6: 245–252, Review. 

3. Xiao Z et al. Strain improvement of Trichoderma harzianum for enhanced biocontrol capacity: Strategies and prospects. Front Microbiol. 2023 Apr 13:14:1146210. Review.

4. Woo SL et al. Trichoderma-based Products and their Widespread Use in Agriculture. The Open Mycology Journal, 2014, 8, (Suppl-1, M4) 71-126.

5. Dos Santos CAM, do Nascimento J, Gonçalves KC, Smaniotto G, de Freitas Zechin L, da Costa Ferreira M, Polanczyk RA. Compatibility of Bt biopesticides and adjuvants for Spodoptera frugiperda control. Sci Rep. 2021 Mar 5;11(1):5271.

6. Zhao C et al. Fungal Warriors: Effects of Beauveria bassiana and Purpureocillium lilacinum on CCYV-Carrying Whiteflies. Biomolecules. 2025 Apr 16;15(4):593.

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